B.Sc Maths

No, you cannot do M.Tech, because M.Tech is a technical degree for those candidates who pass out in B.Tech in their stream for B.Sc students can pursuing M.Sc.

B.Sc (Hons) is much more specialized as compared to the B.Sc (general) degree, and academically, B.Sc (Hons) is a more standard degree as compared to B.Sc (general).
If you want to study any one of the purse sciences (eg. chemistry, physics, mathematics etc.) in detail, it is advisable to go for a B.Sc (Hons) course.
But, if you want a more balanced and multi-disciplinary approach, it is better to pursue a B.Sc (General) course for under graduation.

B.Sc. Statistics or Bachelor of Science in Statistics is an undergraduate Statistics course. Statistics is the study of the collection, organization, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments. There is also a discipline called mathematical statistics, which is concerned with the theoretical basis of the subject. The duration of the course is three years and it an important career orienting in nature that opens many scopes for them. There are many colleges which are offering the course in their campuses in the country.