CBSE 12th

Yes, you can get admission in this college, just follow some basic steps which are:
1
Fill online admission form
a.Choose required course
b.Fill in the required details
c.Submit Form
2
Take Printout
On submission of the form you will receive the detailed mailer at your Email ID. Take printout.
3
Attach required documents
Attach the required documents along with DD to the printed admission form.
4
Post admission form
Post the admission form along with DD to our Registered Office Address.

No, if you have a Diploma degree, then it could be possible. But, there is no medium to get admission directly in 2nd year of B.Sc. IT after one year gap after class 12th.

Yes, you can apply.

What is your locality city? There are lots of metro cities, where you can join the colleges for B.Com (Hons) reply with your locality.

CBSE syllabus has very good reputation all over India. In case of graduation also, your plus two marks will be considered. If you can score better in HSE, then it is good to shift.

You can go for your state government engineering colleges, as you have scored less marks. Or, you can also go for private colleges.

For admission in Jadavpur University, architecture department WBJEE GMR(General Merit Rank ) is necessary along with qualification in NATA. That means only NATA score is not enough for admission in B.Arch, you must appear or have had appeared in WBJEE and secured a good rank. FYI last year i.e. for 2015, opening and closing ranks for general category were 861 and 4767 respectively.
Hope it helps.

Yes, you are eligible for BA in Political Science.

Yes, you can give the NDA exam during your class 12th, but you have to present your passing certificate or marksheet of class 12th during the SSB interview. So, giving NDA exam during class 12th will surely be helpful to you, as you would get a good idea about the pattern and level of written test. But, it will not be valuable for your selection, as you will not be eligible for SSB interview. In a nutshell, though you would not be selected, but I recommend you to surely give the NDA test at least once during your class 12th.

https://www.shiksha.com/b-tech/colleges/b-tech-in-food-technology-colleges-india
You can shortlist your desired colleges from the link above.