Hello,

Admissions to B.Tech programmes take place through national level/state-level/institute-level engineering entrance examinations.

As you taking btech you will have to give Jee exams in order to eligible for admission.

As per the Govt basic criteria, candidates appearing/have passed class XII can apply for JEE Main 2021.

You can give Jee main exams four times in a year and best score will be counted.

The exam will be conducted beginning in February (thereafter in March, April & May-2021) for 4-5 days during each phase.

• For B.E./ B.Tech (Paper 1) – Physics and Mathematics along with one of these subjects Chemistry/ Biology/ Biotechnology are mandatory in qualifying examination.
• There are no age limit criteria for JEE Main 2021.
• Any candidate who has passed class 12th or its equivalent in the year 2019, 2020, or appearing in 2021 can apply for JEE Main 2021.

You can refer to this link for more information.

https://engineering.careers360.com/articles/jee-main-eligibility-criteria

Hope this helps!!