Can I become a physics lecturer after getting into JEE mains??

To become a professor of Physics, a research degree is must and especially a phD degree in Physics. I will brief you how to go to this PhD degree stage and get the degree. In India it is mandatory to follow a +10+2+3 pattern of education to be qualified for the basic criteria in applying for a phD degree. That is,
You should pass 10th class with a minimum first class and this is called +10 years of education
You should next pass 12th class with minimum first class and this is called +2 years of edu after 10th.
Next you should have completed a three year bachelor degree and obtained pass. As you desire of becoming a professor of physics, you are expected to have passed BSc Physics with a minimum first class. Studying Physics related degree is only mandatory and not any other subjects. If you are from reservation category, you can obtain minimum 55% or above through out all years of education.
Completing BSc students can either apply for direct PhD or take a masters route. A Masters route is more desirable as it develops students with more in-depth knowledge in Physics compared to a bachelors degree and it certainly prepares the student well for a research degree like PhD. So you should study a MSc Physics and obtain first class in this case.
Next, write GATE exam and obtain high rank if your focus is studying at IIT institutions. If you dont want to study at IIT, and want to consider other institutions then a UGC-NET score/ CSIR score is essential. You are also expected to have passed UGC-JRF to be eligible for monthly stipend during PhD.
So completing a Phd, you can work at colleges and universities directly as an Assistant professor and after few years of experience and good performance you are likely to be promoted as a Professor.
For studying a PhD in Physics, you can consider top institutes from India like
IIT institutions
IISC Bangalore
BITS Pilani
University of Delhi
University of Mumbai
University of Calcutta
VIT University
Anna university and many more.
Feel free to comment if you have any doubt
Good luck

AIM, you can't simply become a physics lecturer just by qualifying JEE Mains. I will describe the steps you need to follow after that to achieve your goal.

To become a professor of Physics, a research degree is must and especially a phD degree in Physics.

You should have passed 10th standard with a minimum first class.

You should have also passed 12th standard with minimum first class .

Next you need to complete a three year bachelor degree and obtained pass. As you desire of becoming a professor of physics, you are expected to have passed BSc Physics with a minimum first class. Studying Physics related degree is only mandatory and not any other subjects. Completing BSc students can either apply for direct PhD or take a masters route.  So you should study a MSc Physics and obtain first class in this case.

Next, write GATE exam and obtain high rank if your focus is studying at IIT institutions. If you dont want to study at IIT, and want to consider other institutions then a UGC-NET score/ CSIR score is essential. You are also expected to have passed UGC-JRF to be eligible for monthly stipend during PhD.

So completing a Phd, you can work at colleges and universities directly as an Assistant professor and after few years of experience and good performance you are likely to be promoted as a Professor.

For studying a PhD in Physics, you can consider top institutes from India like

• IIT institutions
• IISC Bangalore
• BITS Pilani
• University of Delhi
• University of Mumbai
• University of Calcutta
• VIT University
• Anna university

Feel free to ask if you have any more queries.

Hope this helps!

All the best!