Can anyone please recommend a digital camera, which is very good in low light conditions?

Entry-level DSLRs are much of a muchness, and Fuji's X-series are not DSLRs, and not particularly cheap. You'll be lucky to get a DSLR at £300. I'd strongly advise buying body and 18-55mm standard zoom in any case.

If your lenses are Pentax K, you don't need an adapter with a Pentax DSLR.

If your lenses are Canon FD, you'd be as well throwing them away - they won't fit Canon DSLRs without an adapter, and the adapters are worthless. If they're in Canon EF, you don't need an adapter.

If your lenses are in Nikon F, they won't allow metering with Nikon DSLRs within your budget, so will be of limited use.

If your lenses are in Minolta SR/MD mount, they won't fit Sony SLRs/SLTs without an adapter, which is more trouble than it's worth. If your lenses are in Minolta AF, they'll fit a Sony (A-[2 digits])SLT (not an EVIL model!) without an adapter.

If your lenses are in M42 screw, Pentax, Canon and I THINK (don't quote me on the last) Sony allow Av and M modes only with an adapter - Pentax and Sony also allow anti-shake to be used. Nikon need a corrective element in their M42 adapter, so you'll have a lens half as long again, a stop slower, and no meter.

Any other mount isn't worth the trouble for DSLRs, but most EVIL models can be fitted with adapters for most SLR lenses - if you can deal with the loss of function (no autofocus, limited metering modes, and perhaps no aperture control).

Maybe your old lenses could provide some usefulness, but don't be a slave to them. What mount are they anyway?

If you want wide aperture to help you with the low light, wide aperture has a shallow depth of field. So focus has to be very accurate or it's noticeably wrong, and manually focusing on people moving around can be tough. Then again, if you can prefocus to about a medium distance, maybe sometimes that could give a good result of medium distance dancers being in good focus, and accepting foreground and background dancers being unsharp--something autofocus wouldn't necessarily handle better.

Not within your budget.

You should think about one of the Sony A7 bodies.

The Fujis you mentioned are the X-* series and are not cheap.

https://www.fujifilm.eu/uk/products/digital-camera...

The most sensible thing to do is buy a Pentax or Sony Alpha DSLR body (with Alpha mount, not E mount so look for Sony A33-77) and then you can use any secondhand lens that has their mounts (Sony accepts all the Minolta AF lenses from the late 1980's but not the MD from before)

First you need to know what "mount" your lenses are. Only buy a DSLR which has that same mount. Thus Canon DSLR for Canon-mount lenses, Nikon for Nikon, Pentax "K-mount" for Pentax. But a Sony DSLR for Minolta-mount lenses. (Sony took over Minolta around AD 2006)

Your lenses may be of independent brand, Tokina, Tamron, Sigma, etc, but they will have "mounts" for a particular brand of SLR body.

You can get adaptors for the lenses, to fit other brands of camera, but they give poor quality images, are expensive, and do not support all functions.

Even with "same-brand" you may get lack of support for some functions.

If you know very little about lenses and DSLRs, best to go to a good camera retailer with your lenses, and get advice.

Camera such as the Fuji X-20 or X-30 probably do not have adaptors available for old SLR lenses.

Your old lenses may be highly collectible. While it is true that you can find adapters to mount just about any lens to any body, the adapted lens will most likely have no metering or auto-focus as well as not being able to focus to infinity. If the old lenses are Nikkors, they will most likely fit a modern Nikon body with some limitations such as no metering and/or auto-focus but "will" be able to focus to infinity. I'm pretty sure that old Pentax lenses will work with modern Pentax bodies, similarly. So, look into the lens compatibility before making your decision.

Fujifilm X Pro-1

Panasonic Lumix DMC-LX100

With really good photo and video quality, a great set of features and generally class-leading performance, the Panasonic Lumix DMC-LX100 is probably one of our favorite compact cameras ever. It's not for the inexperienced, though.

Sony Cyber-shot RX100 IV

A nice choice if you're looking for an advanced compact with class-leading video capabilities, the Sony Cyber-shot DSC-RX100 IV is a little expensive if you just want a good camera for shooting stills.

Sony Cyber-shot RX100 III

The Sony Cyber-shot RX100 III is an overall great camera that delivers significant improvements over the RX100 II, but not everyone will think it's worth the extra cost.

Sony Cyber-shot DSC-RX100 II

The Sony Cyber-shot DSC-RX100 II delivers excellent photos, speedy performance, and a broad feature set in an attractive, compact package.

Sony Cyber-shot DSC-RX100

It's been a long wait, but Sony finally delivers a pocketable camera with a large sensor and fast lens.

Olympus Stylus 1

For those who crave an enthusiast compact with more zoom range, the Olympus Stylus 1 should be high on your list for its excellent balance of performance, design, and features.

Sony Cyber-shot DSC-RX1

With a terrific lens and a great full-frame sensor, the Sony Cyber-shot DSC-RX1 delivers the best photos we've seen from a fixed-lens camera. But that doesn't come cheap.

Canon PowerShot G7 X

The Canon PowerShot G7 X would jump from very good to excellent if it could just pick up the pace.

Fujifilm XQ2

The Fujifilm QX2 doesn't improve much on its predecessor, but with its larger image sensor, bright lens and fast performance even in low light, this stylish pocket camera is an excellent step-up from your smartphone or average point-and-shoot.

Fujifilm XF1

The Fujifilm XF1 is one of the nicest-looking point-and-shoots available and it performs well, too. But its photos and features might not please some enthusiasts.

Nikon Coolpix S9700

Outside of some design quibbles, the Nikon Coolpix S9700 puts big zoom power and nice photo quality (snugly) in your pocket.

Secrets and more secrets. Why on earth are you keeping the brand and lens mount of your lenses secret? How can we recommend anything without that information. The only camera that accepts prime lenses from the "film" ara to my knowledge Pentax. Which is comparable to Canon & Nikon in quality.

Your old lenses will not work well with a modern DSLR.

Go and talk to some photographic shops.

Try for new lenses