With Chief's Manipulate power when a char takes a action is going to push can he use more then one Manipulate token to try to avoid that push like remove a token fail the roll then remove another one to try again ?

Always quote the power using the Player's Guide when asking a question, please.

This is from the PG:

o and i was wondering does he have to roll a sucessful leADERSHIP TO ADD A MANIPULate token or just when it would add a action?

Please quote the effect in question. Not only does it help reduce confusion, but a reread can often answer the question.

Manipulate: The Chief can use Leadership. If Leadership would allow you to add an action to your action total for the turn, you can instead put a Manipulate token on the Chief's character card if there are two or fewer Manipulate tokens on the card. When another friendly character would take pushing damage, you can remove a Manipulate token from the Chief's character card and roll a d6; on a result of 3-6, the character ignores the pushing damage.

Since a successful roll is required to add an additional action to the turn, yes, you need to successfully roll Leadership to add a Manipulate token.

Great minds think alike...and I think I've seen vlad post this, too.