With a JEE Main percentile of 46, you may have limited options for B.Tech admissions, but there are still some colleges where you could apply, especially in lower-demand branches. Typically, you might consider:

1. State Engineering Colleges : Many state colleges have cutoffs that could accommodate your percentile.
2. Private Engineering Colleges : Some private institutions may have lower cutoffs and offer various specializations.
3. Deemed Universities : These universities often have their own entrance criteria and may provide opportunities.

It's advisable to check the specific cutoff trends for the institutions you are interested in and consider applying during the counseling process for the best chance of admission.

With a JEE Main rank of 36,852 and a percentile of 82.05, you have a chance of securing a seat in some NITs, particularly in less popular branches. While the exact cutoffs can vary each year and depend on factors like the specific NIT and the branch you prefer, you may be able to get into NITs that have slightly lower cutoffs for branches such as Civil Engineering, Mechanical Engineering, or other less sought-after programs. It's important to monitor the JoSAA counseling process and refer to the previous year’s cutoff data for more precise guidance on potential NIT options.