hello,

the great advantage of dual degree is you can explore more than your b.tech.it will be the good chance to do some good research .then there will be a plenty of time for you to prepare yourself for placement.you can have TAship money.

disadvantage of dual degree:

yes,there will be some issue in dual degree.

some companies wont recruit dual degree holders(PG) for their companies and if you get some bad guidance on research then it will become worst.

the real answer is up to u, if you want to do more and want to learn more or if you felt that UG is not enough for gaining knowledge,then you can go for m.tech

otherwise you can stop with b.tech,you can get placed , earn &  get experience working environment early than m.tech students.

I Hope this information will be useful to you.

if you need additional information,let us know to help you.

Thank you!!!:)