In the long run, it doesn’t really matter from where you do your UG if you get PG or superspecialisation from leading institutes. However, if you are planning for USMLE, then UG from a good institution really helps. More so, if many of your seniors have qualified USMLE from the same institute. Also, if you sitting in any of the interviews for residency, interviewers might take you very easily if you have done UG and internship from good colleges especially AIIMS.
There are many other benefits of doing UG from a tier 1 city. You are going to spend 5.5 years of your life here. And probably you will also get to have PG from the same state unless you get extremely good rank in NEET PG. This is where Delhi has an added advantage. You get to do your PG from Delhi (competition is stiff here though). Moreover there is no bond restriction. Stipened in internship is good. The salary you will get in residency will be the highest in the country.
Besides, there will be good exposure as in investigation, diagnosis and quality of cases in big cities. However it doesn’t matter much at UG level. On the contrary, case discussions and clinical teaching in UG in few state colleges in West Bengal and South India is better than VMMC, LHMC or UCMS.
Overall, it is great if you get a good college. But don’t worry much if you don’t. The battle has just began. Its a long journey ahead!