hi sukh singh, there are many good colleges out there and i shall tell you some prominent ones i know

all india institute of medical sciences

christian medical college vellore

maulana azad medical college

madras medical college

kasturba medical college

JIPMER

PGI chandigarh

university college of medical sciences

sri ramachandra medical college

st.johns medical college bangalore

kasturba medical college , manipal

hope this helps, good luck

Is there any particular state which you are focusing on and generally below provided colleges are considered to be decent to pursue M.Sc in Medical -

ALL INDIA INSTITUTE OF MEDICAL SCIENCES - [AIIMS], NEW DELHI

CHRISTIAN MEDICAL COLLEGE - [CMC], VELLORE

KASTURBA MEDICAL COLLEGE - [KMC], MANGALORE

JAWAHARLAL INSTITUTE OF POST GRADUATE MEDICAL EDUCATION AND RESEARCH - [JIPMER], PONDICHERRY

UNIVERSITY COLLEGE OF MEDICAL SCIENCES - [UCMS], NEW DELHI

BABA FARID UNIVERSITY OF HEALTH SCIENCES - [BFUHS], FARIDKOT

SETH GS MEDICAL COLLEGE - [GSMC], MUMBAI etc.

Good Luck!!!