NIT

Yes, you could appear for the JEE entrance test and apply to NITs, provided you have completed the 12th standard through the Assam State Open Schooling and your qualification is recognised by the authorities. Normally, a candidate should have completed the 12th standard with Physics, Chemistry, and Mathematics, and scored more than 75% (or be among the top 20 percentile in the board examination). It is advised to ascertain JBIC officials about the board's recognition status if you are to be considered an eligible candidate. 

With a CRL rank of 159865 and an OBC rank of 53541, you are unlikely to get admission into a top NIT for a popular branch, but you might be able to secure a seat in a newer NIT for a less preferred branch using your OBC category rank; it's best to check the closing ranks of different NITs and branches on the JoSAA website to see your chances

For admissions to NITs/ IIITs/ GFTIs, candidates should have secured at least 75% marks in class 12th exam or be in the top 20 percentile in the class 12th exam conducted by the respective board. For SC/ ST candidates, the eligibility criteria are 65% marks in class XII.