Is there any point to apply the colleges in cambridge which state their step offer as 1,1 or 1,2? I mean will they let me in if I got 1 and 2 in step ii and iii????
I'm not entirely sure what you're asking, but in general they would give out an offer requiring certain STEP grades in two specific papers which they will specify. The exact offer is not fixed and they may vary it a bit depending on the applicant.
Some colleges will make offers of 1,2, yes. The same offer might not be made to everyone though, so to guarantee getting in, you'd have to match whatever offer you got.