JEE

You can use JEE Mains college predictor for more insights about the shortlisted colleges based on your rank.
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

No board roll no does not create any problem it is just a way to check your 12th result because to check either student in top 20 percentile or having 75% marks or not.
So don't worry it is just of seak of knowledge.

You have to got 75% marks to be in top 20% percentile of college. But nevertheless, you can get admission in NIT-Raipur. But firstly, there is the first requirement. So, you can go for some integrated course in branch selection and then, the internal sliding, you can get the branch as per the requir

Yes, you have a good chance to get admitted in PICT CS.

Your JEE Advance AIR rank must be under 110 in order to get admission in computer science engineering 4 year bachelor degree at IIT Delhi. Last year closing rank for CSE was 115 (general category)

If you are from the science stream, then you can appear for JEE.

Yes, if you scored 170 then you get admission in IITs so don't worry just prepare for exam. Check the rank in which you get admission in which college:
http://josaa.nic.in/Result2016/result/OpeningClosingRank.aspx

Here is a blog comparing CSE and IT. Kindly go through it. Hope this will resolve your query:
https://www.shiksha.com/b-tech/articles/comparison-between-engineering-branches-cse-and-it-blogId-8490

You should but it will depend on your rank.

A pass in 10+2 system of Senior Secondary examination or its equivalent with English as one of the subjects. Candidate must have passed English as a subject of study (core/elective/functional) in the qualifying examination.
Those appearing in 10+2 or equivalent examination can also appear in JEE 2017