Hey !
A Btech graduate have many career opportunities. One need to explore all the options they have before choosing any. If one wants to pursue post graduation..they can choose from a wide range of opportunities , of which MBA is one. Coming to your query, Technical(Btech) and management (MBA) knowledge always comes handy. Now-a- days demand for graduates with Btech and MBA degree is high, as both technical and management skills together form the core part of any organization. High salary is one of the reason students prefer to pursue MBA in Post graduation. Check the below link for more information on  most prefered career options after Btech
https://engineering.careers360.com/articles/what-do-after-btech-mba-or-mtech
Hope this helps
All the best !

Hello! Adarsh.
No there is no issue/problem if you do/take MBA course just right after doing B.Tech. MBA is masters of Business administration.For some jobs companies search or give more priorities to MBA+B.Tech holder compared to only B.Tech holder. Lots many of people doing it. If you do MBA from top Business schools(eg-iim's A,B,C) then your salary can go upto 35-40 lacs/annum. First do some research on this feild and then take decision.

Hope this helps!