dont wry m also not that gud at phy but m hvng gud grip in bio & chem...if u r gud at other subjects then u dont need to wry tht mch...just make the concepts clear in phy
select those chapters which r marks scoring in neet or aiims nd if u r better in chem nd bio give ur full strength on them its enough for selection no need to spend lots of time on phy scoring about 70-80 is enough provided u have to score enough in other two!