Hey Nidhi.

The following collwges are considered the topmost colleges for B.Sc in India.

St. Stephen's College, New Delhi

Presidency College, Kolkata

Lady Brabourne College

Banaras Hindu University

Jamia Millia Islamia

St. Xavier's College, Kolkata

Jadavpur University

Jamia Hamdard University

Gargi College

Daulat Ram College

St. Xavier's College, Mumbai

St. Josephs College, Bangalore

Guru Nanak College Chennai

St. Andrews College of Arts Science and Commerce

St. Thomas College Palai, Kerala

Andhra University Faculty of Science

Loyola College, Kanpur

Shree Shakti Degree College Kanpur

Presidency College (Chennai)

St. Xavier's College - Ahmedabad

Fergusson College, Pune

Madras Christian College

Christ College/University, Bangalore

Mount Carmel College, Bangalore

Kalinga Mahavidyalaya, Kandhamal, Orissa

Hans Raj College, Delhi/NCR

Hope this helps. All the best..