The Indian first funding does not go directly to students. It goes to first nations and Inuit administering organizations. So it's distributed across the country to Indian Affairs regional offices, which then distribute to the administering organizations.
There are a variety of formulas used in different regions. That kind of distribution to the first nations and Inuit administering organizations would typically happen through a discussion between the regional office and first nation organizations. So typically there's first nations input into that kind of allocation.
Generally there's a population basis for how the money comes to be distributed. Different regions use different kinds of calculations. Some might use an age-specific population basis; others might use a general Indian-register population basis. There's always a connection to some kind of population basis when they determine how the funding will be allocated to first nations and Inuit organizations.