can I make money playing tight aggressive 3-6 hold em....I'm a solid player but could I make this a profitable semi-pro endeaver?

It's said that in Limit hold'em, a winrate of 1 big bet per hour is the goal. In 3/6 maybe a higher winrate would be possible given the weak competition, except the rake is quite high so it's doubtful that you can earn more than $6/hr in that game. If a wage of $6/hr is what you'd consider semi-pro then sure go for it.

But be aware that, while playing TAG should give you an edge over the calling stations, the edge won't automatically be large. To crush the game (and to eventually move up in stakes) you'll have to actually get good.

If you always have a good read on your opponents and play with no fear, why would you have to play TAG all the time?