B.Tech

http://www.bitsadmission.com/Eligibility_Criteria.aspx check this

Hello Aditi,
Your probable rank will be around 24-25k. However, check here for your probable colleges:
https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/b-tech/resources/wbjee-college-predictor&ved=0ahUKEwis-YO6sp7UAhVGzlQKHaWWBVwQFghNMAQ&usg=AFQjCNHFdGxPSyaEpuQL-rFHAhIPZe

It will be around 1.5 lakh rupees per semester.

Hello Chandan,
As per your rank, you will get lower branches in Jadavpur University. However, check here for more insights:
https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/b-tech/resources/wbjee-college-predictor&ved=0ahUKEwis-YO6sp7UAhVGzlQKHaWWBVwQFghNMAQ&usg=AFQjCNHFd

There are certain scholarships schemes available in BITS-Pilani for students.

In computer science with applied mathematics, students can design and implement algorithms.
They can apply mathematical and statistical techniques to solve problems.
In computer science and engineering, students cannot go for higher mathematics research.

Dear Alok,
Yes, you can do it you can also get admission in 2nd year of engineering. There are many universities available which provide B.Tech through distance mode Karnataka state open university, Jaipur University, etc.

MS Ramiah is one of the best college of Bangalore that takes admission through COMEDK. So, you have to score good in COMEDK.
No doubt this college is really good. If you are getting admission, then you go for it.
All the best.