Hello Ajay,

NITs are the India's second topmost technical institutes and every student want to get a seat either in IIT or NIT. But it's not a easy task. Students work very hard to get into this institution and combine their blood and sweat for the best results so that they may get their desired branch in the desired campus.

Admission in NITs are done only and only on the basis of JEE main results and there is no other criteria to get into this institution. So if you had missed the JEE main then you can not get into this institution by any way this year.

You have to take a drop and wait for the next year JEE main and have to take the JEE exam and bring a good rank to ensure your admission in one of the NITs in your desired branch. 

A huge congratulations for your boards results but to take admission in NIT's or any other government institutions for BTech program one needs to compulsorily take the JEE main and advanced in case of IITs and clear it with a very good rank .

But yes you can take admission in any private colleges where they give you admission on the basis of your 10+2 results and in this way you can simultaneously prepare for your JEE also and continue your further studies as in this case no loss is there as if next year you get the NIT you can go there and start from year 1 and if not you can continue in private college in year 2.

Hope this helps.

Further if any queries feel free to ask.

All the best!!

Regards.