Hello, 

These are some of the colleges in india that offer distantce education in BSC. Mathematics. 

• Wisdom School of Management
• Institute of Distance Education, University of Madras
• NSOU - Netaji Subhas Open Univesity
• Directorate of Distance Education, Alagappa University
• Nalanda Open University - NOU
• CVRU - Dr. C.V. Raman University
• TNOU - Tamil Nadu Open University

To know more about the colleges, please go through the following link 

https://www.shiksha.com/science/colleges/distance-correspondence-b-sc-in-mathematics-colleges-india

Hope this helps .....