The mock seat allocation is based on the candidates' choices.
Although the mock seat allotment is not perfect, the percentage of accuracy is determined by the rank
It should also be noted that not all students are able to finalize/complete their choices for the mock seat allotments
There is always a lot of uncertainty until the choices are locked.
The top rankers are those who are very serious about admission and will not leave their seats for drop or admission to other institutes such as NIT, BITS, and so on.
As a result, the mock seat allotment will be 100 percent accurate for the top 100 ranks.
It could be 99% accurate between 101 and 500.
It may be nearly 90% accurate between 500 and 5000, and so on.