Yes, you can leave NIT midway in January if you choose to, but there are some important points to consider before making that decision:

1. Official Process & Consequences

• Most NITs allow students to withdraw, but you’ll need to follow proper procedure (submit a withdrawal form, clear dues, etc.).

• Refund policies vary , and you might not get your full fees back, especially after one semester.

• Some NITs might mark your academic record with “withdrawn” or similar; it's not usually a big issue, but something to be aware of.

2. JEE Advanced Eligibility

• You can attempt JEE Advanced only twice in two consecutive years after Class 12. So, if you passed 12th in 2024, your last chance is in 2025.

• Joining NIT and preparing for JEE simultaneously is tough but possible. Many students take a drop year instead of joining to stay fully focused.

3. Have a Clear Plan

• If you're confident that with full-time prep you can crack JEE Advanced and get into an IIT, then yes, you can leave.

• But don’t take the decision in a rush or out of fear. NITs are excellent institutions too. Make sure your goal is clear.

Suggestion:

• You could start at NIT in August , see how it feels, and prepare alongside.

• If by December you feel strongly that you need full-time prep, then withdraw officially in January.