B.Tech

Hello Neha, I am attaching a link for your query please go through it
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=7576872
Good luck.

You can get a government college. I suggest you to get the details regarding the government college which take admission on the basis of JEE Mains since you have qualified with very good marks. Wait for the counseling procedure and keep the plan B for an emergency option if didn't get the college then you can get the another college or private which you have kept as option B. https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor
Use the above link for predicting the college:
Best of luck.

If you have scored more than the cut-off marks that is from very big margin you have qualified the JEE Mains in your category then only you will get the college. https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor
Check the link for predicting the college on basis of your rank. Best of luck.

Yes, you are eligible for SAP SD because the eligibility criteria for SAP is graduate.

Yes, ofcourse. It's a good field but if you have interest in it because there are big opportunities in this field. But you have to grab it because big opportunities also have big competitions. So, choose correctly and proceed well.

If you are interested in pursuing B.Tech in any of the private colleges in North India then Chandigarh University may be the best option that you can opt for. The details you may require are here:
http://www.cuchd.in/placements/cu-recruiters.php.