Hello,

According to what I know and informations I have gathered, Mathematics and Computing in IIT Guwahati is a good choice especially for people who are very enthusiastic about computer science. It's not a dull branch. Many of their courses are same as that of CS Dept. Unlike CSE it is extremely maths intensive and also has a Computer Science depth in its syllabus. The maths in the beginning of the course adds to the breadth of your mathematical knowledge while later the maths is confined to statistics and finance. The course has an overall low syllabus flexibility but becomes flexible enough in the last two semisters.
The job opportunities are also decent for the branch. Most of the companies that open for CS are open for M&C too.

If you hate finance it's hell for you: Owing to the inflexibility of the current syllabus dropping finance courses out is impossible and the courses are quite a struggle for the disinterested.

Hope this helps you.

Good luck!