Hey, for entrance exam in MSc mathematics most of the institution's eligibility criteria are that you should Mathematics and English as the main subject with minimum 50% aggregate, however, some institutes even prefer students with a B.Sc. /B.E. /B.Tech. degree.

mostly the syllabus for Entrance exam in MSc Mathematics are

• Real Analysis
• Linear and Abstract Algebra
• Calculus
• Topology

I hope this helped.

best wishes