NIT

With a percentile of 63 in JEE Main, admission to NITs or IIITs can be challenging.

While a percentile of 63 opens up opportunities for various engineering colleges, it may not be sufficient for NITs or IIITs, as these institutions typically have higher cutoffs.

Admission to NITs and IIITs is competitive, and candidates with higher percentiles are generally preferred for these prestigious institutes. 

With a 96 percentile in JEE Mains and belonging to the OBC category, you have good chances of securing admission to various colleges.

Some potential options include NIT Raipur, NIT Agartala, and NIT Goa for branches like Mechanical Engineering, Chemical Engineering, and Electronics and Communication Engineering.

Additionally, other government colleges also accept this percentile range for admission into popular specializations like Mechanical, Civil, and Chemical Engineering. 

To secure admission to NITs with a 90 percentile in JEE Main, you have a good chance. NITs like Agartala, Meghalaya, Raipur, Jalandhar, Durgapur, Goa, Puducherry, and Hamirpur accept scores between 80-90 percentile in JEE Main 2024.

 This percentile corresponds to a rank between 150,000 to 300,000.

While admission to top NITs can be competitive, other esteemed engineering colleges also accept this percentile range. 

The eligibility criteria of NITs includes that the applicant must have minimum of 50% in boards with mathematics assignment main subject.

50% in boards+a decent percentile in JEE paper 2 are considered for admission in NITs. However it varies for various NITs.

So, the conclusion is that one should have minimum of 50% in boards and should have secured qualifying percentile in JEE main paper 2.

NIT or any other Govt college with certainly 100% certainty in your SC rank of 69841 provides a good chance of getting into these college. 

The NIT JEE cut off inclusing top NITs like NIT Trichy, Surathkal is 900- 60000. This year the cut off is going to get released in June so wait for the rank and compare it with the previous year cut off to get into any good NOT or Govt college.

Unlike NITs and CFTIs, the IIITs accept candidates up to JEE Main rank 54,000 in the open and gender-neutral category. They mostly offer popular courses like Computer Science Engineering, Electronics and Communication Engineering, and Information Technology to the candidates who rank above 25000 in JEE Mains.

Some of NITs and IIITs which offer computer Science engineering are

• IIIT's Like IIIT kota, IIIT Guwahati, IIIT kalyani, IIIT sonepat, IIIT vadodara etc.
• NIT's Like NIT Hamirpur, NIT Meghalaya, NIT puducherry, NIT Sikkim, NIT Uttarkhand etc.

NIT and IITs always has its cutoffs and ranks higher. As you have mentioned your AIR in JEE Mains under OBC quota is 104,000 rank. So with this rank, I am sorry to say that you will not get any NIT.

A rank of 75,000 to 1,00,000 in the JEE Main is equivalent to a percentile of 93, which may not be enough to get into top NITs like NIT Tiruchirappalli or NIT Surathkal. However, some other NITs, such as NIT Calicut or NIT Meghalaya, may accept this rank.

Nevertheless for your own reference you can check the different NITs cutoff through this link:

https://www.shiksha.com/engineering/articles/nit-cutoff-blogId-20217

As there are more NITs cutoffs varies from city to city and also the caste category.
So if you are SC the cutoff will be averagely 2000 to 5000
For home state at open category

• Chemical engineering - 15073 to 20271
• Mechanical Engineering- 3741 to 13216
• EEE - 6980 to 9878

For Other states at open category, 

• Chemical engineering - 3000 to 11137
• Mechanical Engineering- 3357 to 7320
• EEE - 2608 to 4818

So the cutoff will be variying upon your caste type and also the state you are in.