Hello Friend,
After B.arch there were several opportunities for the your career you can opt for job or you can continue your higher studies. As you completed B.arch with Civil engineering is good about you.

Of course, yes you can go for M.tech after B.arch and i think its not wise decision to opt because Mtech is the technical field course and you are form the Architectural field there is lot of difference between them.

As you can also do M.arch after B.arch and it is also good option to do and i suggest you to go for it as there were some course which offers better opportunities of jobs.

I suggest you to do Master of Design(M.des) which is also known as POSTGRADUATE DIPLOMA PROGRAMME IN DESIGN(PGDPD) was the best way after B.arch. As there were various opportunities of jobs