Is it good to do B.Tech in CSE and then apply for B.Ed or B.El.Ed? What opportunities will one have if to be computer teacher is the aim?

If you aspire to be a computer teacher then join B.Ed because that is more targeted course than B.Tech in CSE.

For becoming a computer teacher, you have to apply for B.Ed. It will save your time and provides you more opportunities. Nowadays there are too many students who opt B.Ed or BTC course after B.Tech.