12th science (PCM) with 55% which engineering colleges I go ?
see as you score this percentage you can go to any private college of any region but their are college which are private but still have maintained their respect so may be at this percentage You cant go but in college private college in Jaipur which are not bad and also select directly without any exam or having low percentage .....so you shoud serch in jaipur Rajasthan
Your selection will be immensely depending on the category you are belonging to. It will tough for a good selection if you are belonging to general category since general category eligibility criterias are usually 60% and above.
If you belong to any category other than General, then you may have a chance to get into prestigious colleges of the country. But if belong to General category, then you better start preparing for upcoming Engineering Entrance Test.
I don't think the government colleges will be ready to take you in with that aggregate. However, try for the private colleges. Most of them have a 60-65% cut off for Boards but let's hope for the best!
Chennai mathematical institute
Indian statistical institute
Etc etc
But rather than go for that firstly improve your marks and then apply for jeemains,bitsat-fee-structure,wbjee
Etc
Where YOU want to studies