Can car be repossessed if pay on the past due amount?

"Pay on" - sure - your still in breach of the payment agreement and owe the debt - just by a lesser amount. (The lender has the obligation to do everything to mitigate (that means lessen) his damages...that would seem to include accepting partial payments which act to do so.

"Pay off" all amounts due - then no repossession should occur - there is no debt to be in default of not not paying.