Here is how the process works
1) You get an Offer Letter (Not letter of Admission)
2) You pay the tuition deposit
3) You get a letter of admission and IRCC letter.
4) In case of SDS, you pay the first year fee in the college.
5) In case of Non SDS, you pay first semester fee in the college.
After this, you apply for the visa by attaching all other required documents based on your case.