How does the NIFT counselling upgrade algorithm work?

Hi! I had a quick doubt about NIFT M.Des counselling.

I got Gandhinagar in Round 1, and it remained the same in Round 2 (Open Rank 83, CMR 103).

My preferences list is as followed

Delhi > Bangalore > Mumbai > Gandhinagar > panchkula > kannur > kangra

If I'm currently allotted my 4th preference (Gandhinagar), and in a later round both my 2nd preference (Bangalore) and 3rd preference (Mumbai) have vacancies, will the algorithm first check Bangalore and allot it since it's higher in my preference list? Or does it start from my current allotment and stop at the first available upgrade (Mumbai)?