if we top with normal air into nitogen filled tyres what will be outcome ?

smoothnes

reduce punctre risk

cool in summer

chek ur tyre pesure after 4 months

There will not be an issue, the main reason for using nitrogen in car tyres is to ensure there is no water vapour, and has only marginal benefits to a road car.

Nitrogen makes up the vast majority of the air you breathe, so don't worry.

Perfectly all right. Exactly the same as if you had originally filled them with air. Air is 78% nitrogen to begin with so using 100% nitrogen really does nothing to improve the performance of car tires. 100% nitrogen is used on airplane tires because there are benefits if you happen to go from temperatures of -60 to +100 in a few minutes. Airplanes do that several times a day when they descend to land. Someone discovered that motorists are willing to pay extra for nitrogen filled tires and so they started selling nitrogen.

All will be fine.