IIT

In order to have an idea about syllabus of B.Tech CSE, you may refer to following link:
https://www.iitr.ac.in/departments/CSE/pages/Academics+Course_Structure_BTech_in_CSE_New_.html. Syllabus is similar in all IITS with minor differences.

If this is your rank in JEE Advanced under general category then you can get mechanical engineering in an IIT. You may not get IIT Bombay, Madras, etc. but you may get Mandi, Jammu, etc.
These are also good IITs and they are better to study.
BITS Pilani is really costly so if you get any IIT then drop BITS Pilani. If you can take loan and if you don't want an average IIT then go for BITS Pilani.
For previous year opening and closing ranks refer:
http://josaa.nic.in/Result2016/result/OpeningClosingRank.aspx

Hello Abhishek,
Please refer to this linl to get more insights of the colleges based on your rank:
https://www.resonance.ac.in/reso/news/jee-advanced-branch-allotment.aspx

Hello Karthik,
I think you can get the top IITs like Madras, Bombay, Kanpur, etc. if this is your AIR.
for the official opening and closing ranks for 2016 refer :
http://josaa.nic.in/Result2016/result/OpeningClosingRank.aspx

Mahatma Jyoti Rao Phoole University
University of Rajasthan
IIS University
Subodh College
NIMS University
Maharani College
Rajasthan University of Health Sciences

Some IITs do offer robotics but not at B.Tech level. Robotics is offered as a subject when you approach for M.Tech in IIT Kanpur, Mumbai or BHU. But if you want to pursue robotics later, it is advisable to choose Mechanical, electronics or computer science at B.Tech level.

By your JEE marks, you are not getting IITs and your advance marks in not so good that you get IITs you can get NITs or any GFTIs by this rank so you take part in the counseling from 19th June.
All The Best.

Please go to the following link and check the participating institutions.
https://www.jeeadv.ac.in/

No, you cannot appear for IIT-JEE after 2 years from clearing 12th.