How should a second year CS student at BITS Pilani, Pilani Campus prepare to get an admit to MIT/Stanford?

Maintain a Good Cgpa > 8.5 atleast. Do SOP under a good faculty, SOP will count as DEL. Go for TS instead of PS in 4th year. Keep Participating in national level techfests. Get a Good score in GRE. Use DC to enquire more about Resources for studying in these univ… trust me DC is very useful for it. Try contacting seniors who are currently studying in top ivy league univ. Since you are from CS I don’t think much of your seniors may have gone for further studies in the univ abroad since most of them get placed. So look for seniors in other department and try to get info from them.