Heat is the key to loosen the bolts off - I use a butane torch, if you have access to oxy torch, they can be carefully used too. Keep it local to the bolt as it can affect the rotor magnets which may or may not be an issue for you if you are replacing the actual rotor). Then for the knackered bolt heads, find a sacrificial Torx bit or the right size to jam in and hammer it in to the where the hex socket used to go.
Now you just need an Impact screwdriver and whack away until the bolt frees off.
Your question implies that you are still in the process of removing the rotor from the bike, I can see the rotor removal tool is still wound into the centre. If you are finding it is stuck on the crank, you need wind the bolt in tight, hit the end of the bolt with a hammer to shock it, wind it in a bit more, hit it again, repeat until it goes. It's a tapered fit onto the end of the crank and will pop off suddenly when it's ready.
The six hex bolts are not required to be removed to get the rotor assembly off the crank, they just affix the rotor to the starter gear. I'm just mentioning this as it's not clear as to the purpose of you removing the rotor at this point.