iPad 1 requested activation after being low on power. Activation does not work.

Hi

My iPad 1 requested activation after being low on power. Activation does not work so I have tried to restore it from iTunes. this progresses but after rebooting, it gets to the activation process for a few minutes and re-boots again - in a loop now. on ios6, not 7. help please?

I also looked at trying to do a manual install of firmware via iTunes but I do not know the version of firmware or how to find it out - so really stuck!

Thanks