guy is it possible to balance charge rx lipo pack that doesnt come with balance tap??

No, its not. You'd have to pull end apart where wiring is and add balance tap wiring. Some lipos are just made with no intention of being balanced. I've had several - mostly 2cell, but have had 3Ss as well. Still using several and they're doing fine.

Just use them till they start to degrade (mine went well over 100 cycles) and then replace them with ones with taps. If it really bothers you not balancing them, every so often charge at a very slow rate - that will help balance them.