Anyone know the best way how to drive tposts into rock?

Good luck on this quest. Only ways that I know of large air compressor with rock drill, generator with heavy duty hammer drill.
How many post holes needed?

Use an air drill first?

Need 10

Making a fence around feeder

If the rock is solid a good option is to use a hammer drill with 1/2" bit, then use 1/2" rebar instead of a T-post. Once the rebar is driven into the hole it will be plenty solid. Been there.

I built a fence around my camp using t-post earlier in the year. Used a hammer drill w/ a 1.5" bit. It takes awhile to drill the holes but you're only doing 10, so about an hour or so. After drilling, use a t-post driver to pop the t-post in, it should fit very tight. Push the dust from drilling back around the t-post. It will harden back up after a rain.

1/2" hole like TxAg is suggesting will be a lot faster. The 1.5" hole takes awhile to drill, trust me. I drilled between 40-50 of them and it took darn near all day.

Be sure to knock the plate off the Tpost before you try to drive it.

You asked if anyone knew the best way, so IMO it's get access to a skid loader or tractor and put a puffer bit on it.
It'll drill through solid rock and clean the dust out of the hole at the same time.
Takes about 5-10 minutes a hole.

I would try making a round pen out of panels, it will probably stand on its own without posts. If not there are pictures of some braces someone make on here for this purpose to set a pen on rock.

If you're only doing 10, the hammer drill will get it done. That's what I use at me place in Carta Valley

This is the work smarter, not harder methodology. There are only a few reasons this wouldn't work. Would definitely try this first. Without the right equipment, getting Tposts in rock sux.

I have shape charged 1 lb tannerite to loosen things up