Hello Debajyoti. I think in the first year you should focus on the university exams. First get used to mbbs and then you can go for pg in your latter years. The material made by marrow is for pg level and based on past year pg papers. But for university you will need theory and practical knowledge that will not be provided by marrow. You can visit their official website to apply for marrow. The link is given below.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.marrow.com/&ved=2ahUKEwjd3IT3i8bjAhVHSX0KHRvTC-kQFjAKegQIBRAH&usg=AOvVaw1s8Rb0x7EHjsk8EZXRdqdJ&cshid=1563715077632