What are the IB hl subjects mandatory for joining engineering colleges in TN?

Hello Uthra, since you have mentioned the VITEEE tab, I believe you are concerned about its eligibility to get into a Tamil Nadu engineering college. The subjects has to be chosen depending upon the eligibility criteria. So the eligibility criteria of the VITEEE examination conducted by the Vellore Institute of Technology is based on various particulars, i.e. , nationality, age, qualification, qualifying marks and subjects, year of passing.
Nationality
It is not a barrier, as a resident or a non-resident indian you can apply for the exam. As well as the foreigners can apply through a foreign national application form.
Age
If you are applying in VITEEE 2019 then your date of birth should be on or after 1st July, 1997.
( Also, the authentication of date of birth depends upon class 10/ SSC or High school certificate)
Qualification
The aspiring candidates should have completed any of the following to appear in VITEEE:
1. Passing 10+2 examination through CBSE, ICSE or any other State board.
2. Giving a pre-university examination or intermediate through recognised board or university.
3. A High School Certification from Cambridge University or International Baccalaureate Diploma from the International Baccalaureate Office, Geneva.
4. Any General Certificate Education(GCE) from Cambridge/London/ Srilanka with an Advanced 'A' level.
5. Students from National Institute of Open Learning (NIOS) can also appear for the examination.
6. Candidates should have studied full time, regular education.
Qualifying marks and subjects
1. A score of 60% and above in the subjects: Maths/biology, chemistry and physics, in 10+2 examination.
2. In the above mentioned subjects, candidates from SC/ST category should score 50%.
3. North-eastern candidates should have scored 50% and above in all the subjects.
4. Only the students who have studied Maths, biology, physics and chemistry are eligible to apply.
Candidates should have Physics, Chemistry and Biological to do B.Tech in Bio-Technology and Bio Engineering programmes.
For more details, refer to : https://engineering.careers360.com/articles/viteee-eligibility-criteria
All the best!
I hope this helps.