Hello Sanjay

For admission to mbbs or any other medical courses like bachelor of Physiotherapy, Ayush, Vetrnary, bachelor of homeland medicines surgery,  bachelor of Ayurvedic medicine and surgery seats  are given either through state counseling process or All India quota process.
There are 85 percentage state quota seats and 15 % AIQ( All india quota )
Entrance exam - Neet / aiims / jipmer
State quota seats are given to only those students who belong to that state and they have domicile of that particular state.  For example if a candidate is from maharashtra then he or she must havd maharshtra state domicile and the candidate will be eligible for state quota seat . A candidate from other state , uttar pradesh can get mbbs seat in Maharashtra through AIQ.

But getting AIQ seat is not so easy. There is higher cut off for AIQ seats .

So a candidate from other state may get mbbs seat in Goa through all India quota .