Even if you've been here more than 3 years?
No. There are 10 categories of people who are eligible for Home fees for Higher Education in England, Wales and Northern Ireland, and only 2 of them require ILR, plus there are some additional concessions for Further Education courses. For Scotland, there are 14 categories of Home fee payer that apply across both Further and Higher Education.
See the UKCISA info sheet posted previously.
It is not correct that different universities apply different rules. The rules are the law of the land, and must be applied. Different universities do sometimes make different assessments of the same person, but that's usually because they have made a mistake, not because they are applying different rules.