i m pursuing my B.E.(mech Engg)&my qualification will be 10+3+3 after graduation.I m want to do MS in US but in most universty demands10+2+4

In your case, you have 2 options: 1) Either to pursue a PG diploma of 1 year duration and then apply to US. This is the only way you can make yourself eligible to study in US or 2) You can pursue a degree in UK, Australia, or Europe.

they wish 16 (10+2+4).....u just acknowledge them that you are also fulfill 16(10+3+3) pattern , I think u completed ur Diploma first than join B.E right...than no problem you took authorisation letter of your college/Mentor that ur course is equivalent to 16 and apply for it......I think it's helpf