The right decision after B.Tech would actually depend upon individual goals and interests in the domain of data science. Here's a dissection of the choice and elements involved:

M.Tech in Data Science: This course will see an emphasis on developing advanced technical skills and having theoretical knowledge. The benefits of doing so would be that you will garner a much deeper understanding of algorithms, data structures, and other advanced data science techniques. You would be targeting research or more highly technical roles.

Disadvantages: More theoretical with lesser industry-oriented as compared to M.Sc. programs.

M.Sc. in Data Science:

Focus: Practical skills with more applicability to industry.

Benefits: Builds up good problem-solving, data wrangling, and communication skills along with technical knowledge. Provides a good foundation for getting jobs as a data scientist.

Disadvantages: In-depth theory may be given lesser importance as compared to M.Tech. programs.

Here are some other points to consider:

Your Career Goals: If you are targeting research-oriented roles or intend to pursue a career in academia then M.Tech would be a better option. If you are targeting industry jobs, M.Sc. is mostly preferred.

Work Experience: If you have substantial work experience after B.Tech, short-term intensive program may be more time-efficient.

Your Learning Style: If you prefer theoretical rigor, go for M.Tech. Want more practical applications? Take M.Sc.

Alternatives to Consider:

Boot camps and Online courses: Highly intensive and accelerated programs to enter into data science careers in a very short period.

Masters by Research (M.Res.): A mix of coursework and an associated research project. That is, in case one needs to go into research but does not want to commit to a full M.Tech.

The right course is that which best suits the career desires and the learning behavior. Do research on the specific programmes, curriculums and outcomes.

Here are some resources that will help you further:

Universities offering M.Tech or M.Sc. in Data Science: There are many Indian institutions that offer these courses. Research IITs, IISCs and reputed universities.  Data Science Bootcamps: Websites like Coursera, edX, and Udacity are offering intense data science bootcamps.

By considering all these factors, you can make a well-informed decision about the best path to take your data science skills to the next level. https://www.careers360.com/courses/msc-in-data-science