Hi aspirant,

Normally the seat allocated by based on some factors such as give below
At first authorities considers the category, which also includes GEN, OBC-NCL, SC, etc. Based on the category the authorities also allocate the seats.
Secondly, the position of the candidate in rank list is much important because the seat allocation also based on the rank so every candidate need to get good scores in this examination, scoring good mark is the way to get seats in their favorite institution.