Hey

There are a few colleges in India that are offering internal pg qouta to ug candidates. The ones that I know are

1. BHU Varanasi - probably the first name that comes into mind after hearing internal pg. BHU is the best option for people not belonging to Delhi as the quality of education is great and the ratio of ug pg is also good.
2. VMMC Delhi - for all India seat you need to get an all India rank under 100 and you can also apply for Indraprastha University form which also has some all India seats this year last seat was given around AIR 400.
3. AFMC Pune - this year when I went to AFMC for medical there was an interaction between the faculty and the candidates and during that one of the professors said that there is 100% guarantee of pg for AFMC cadets and it is absolutely true. But certainly there are service bonds after that. It is also the best college for UG in this list.
4. AMU Aligarh - similar to BHU but closer to Delhi.
5. CMC Vellore - I am not absolutely sure about this but contacting my seniors and some people on qoura last year during my counseling I came to know that during admission procedure of pg in CMC Vellore an interview is taken in which internal candidates are more favoured            good luck