B.Tech

Yes. You can opt for EWS category.

Congratulations on finishing your degree.
Since you have mentioned that you would want to continue for postgraduate studies, it is not clear if you want to continue on the same branch or management related branches.
Generally, marks don't matter if you score above sixty five percentage. However, your

You can go for DTU, the best in Delhi.

National institute of technology, kurukshetra is considered as one of the most prestigious technical Institute in our country. I will give some points regarding the college here:
Departments:
CS/IT department : This department bags the highest placement packages every year. The coding culture is very

Yes you can easily get best colleges of IPU under this rank and if you are delhite then it will be a piece to cake for you, use techbits rank analyser to get the exact approximation of colleges you can get.

DU has only one Engineering college named NSIT affiliated to it. It is among top 20 Engineering colleges of India with excellent facilities, faculty, brand image and campus placement records.

Yes, it's good even I have friends who do the same. I would suggest you to attend some coaching classes during your B.Tech because that effects a lot and B.Tech life has so much leisure. Apart from this, after you complete your B.Tech, go for IAS coaching and then attend UPSC exam.
Good luck.

Just go through the link josaa.nic.in which will give you the details of the opening and closing ranks of NITs, IITs, etc. through which you can easily know your college.
Good luck.