I have written intermediate. I am interested in physics teaching (+2 level / high school level). Shall I take engineering degree in ECE or B.Sc. degree and later take up M.Sc.? Does engineering graduate have any advantage over normal graduate in teaching?
As you have mentioned that you are interested in teaching, its better to pursue your B.Sc followed by a master degree in Physics. Requirement for teachers in pure science (Physics, Chemistry and Mathematics) disciplines are very high. There is an acute shortage of qualitative faculty in Physics, Chemistry and Maths.
There is no retirement for this kind of profession, as long as your teaching quality is good. It is a highly lucrative job in recent times and for ever also. I strongly suggest you to go for B.Sc followed by MSc in IITs by appearing JAM entrance.