i hit a concrete pillar and I was looking at the damage and noticed the tailgate on the passenger side,the side i hit, is now to close to the body. the tailgate is over lapping the tail light body panel and now i cant open the tailgate without bending the corner of it.

You shouldn't have hit that concrete pillar...

Not exactly easy to diagnose/repair body issues via the internet. Your best bet is to take it to a body shop and have them fix it.

If the damage is what I think it is, you could (DISCLAIMER DO THIS AT YOUR OWN RISK AND DON'T BLAME CATHEDRALCUB FOR THE RESULTS) (UNLESS THE RESULTS ARE REALLY REALLY GOOD) find something solid to tie to next to the truck on the bent side, chain it to the top of the bed rail with a winch in the middle, pull real hard. You'd probably want to spread the pulling load over as much metal as you can on the bed rail so as not to bend anything more than it already is. Maybe use two or three winches in parallel and increment them accordingly.

Just an idea.

AGAIN DISCLAIMER YADA YADA DON'T BLAME ME OR ANYONE ELSE UNLESS IT COMES OUT REALLY REALLY GOOD. YADA.