JEE

Based on your percentile, it is not possible to get a seat in any NIT or iiit. Even obtaining a seat in the new iiits via CSAB special round counseling seems very hard. Now coming to other government colleges, you can apply to the colleges accepting admission through JEE Mains. As I have heard, maybe UPTU is planning to take admission by JEE Mains. Look to it, this is not confirmed. Apply to other state colleges accepting Mains result. Give other exams too, I am sure you can get good rank in state exams. Or the other option left for you is to prepare again for JEE and do better this time, you will atleast need a percentile near to 97.5 percentile and above to secure a seat in central colleges considering your category. Try and choose wisely if you are going to take admission this year, do not go for Mains counseling, it would be a waste of time.

In the absence of your category-based rank, it is difficult to accurately answer if you can or cannot get NIT-Andhra Pradesh (Tadepalligudem). But based on the previous year's cutoff for B.Tech in the Computer Science and Engineering branch, it could be said that you cannot get NIT (Tadepalligudem) if your general category rank is not under 17,400 in JEE Mains. The reason is that CSE is one of the top branches, and therefore the competition is high, as evident in the 2020 and 2021 cutoffs. For example, in 2021, the general college rank for admission was 17348 while it was 14025 in 2020. Even with category-based exemption, one must have a rank of less than 20,000 to be admitted to the NIT, Andhra Pradesh.

Your strategy totally depends upon your goal, and upon your situations. Speaking about a general, non-ews student, you need a percentile greater than 92, for which you'll only get a seat in the spot round, for biotech or mpae at NSUT/NSIT. Marks anywhere around 110 to 120 could be enough, considering the exam is now of 300 marks. Strategies that could work would be -
Download subjectwise JEE Mains archive for previous years. Revise the notes/formulas/questions practiced of a particular chapter of your choice each day and then attempt just the JEE Main part of archive only (leave out the JEE advance questions), and complete 1 to 2 chapter (for Physics and Maths or upto 3 to 4 (for Chemistry each day. Try to analyse what mistakes you made and how would you correct them, the very same day. Just simply watching the solution on YouTube or on Google will be enough. After a month, you would have covered most of the syllabus considering you do as said sincerely. Now download all the 16 question papers of JEE Main 2019 and the 8 question papers of JAN, 2020. Attempt 2 complete tests each day and don't forget to learn from your mistakes. Before starting your tests each day, just revise formulas or notes for any 5 chapters of your choice. And next 5 the following day and then similarly the next. By doing this you'll not forget formulas and also learn how to attempt the exam simultaneously. Leave everything on the day before your actual exam and just relax and have faith in your hardwork. I used this strategy myself last year and was able to get a 96+ percentile. All the best!