An acquaintance of mine completed his PGDM from IMT Ghaziabad so hopefully, he would be able to answer your question accurately.
The college management may ask full-time students to choose their specialization area before their placements for summer internships which are usually 3-4 months of joining even though technically you can choose your major by the end of the first year. My acquaintance had to choose his major before his summer internship placements.
If you choose PGDM Full time, then you will be able to choose your specialization from:
If you go for PGDM finance, you will have to learn the electives and core subjects of finance in your second year.