Jayalalitha and Mayawati both got their start as mistresses of male politicians.
True for Jayalalitha. But CM of WB Mamata Banerjee mostly made it on her own and Mayawati's power base mostly overshadowed Kanshi Ram by the mid 1990s. Also the weather Mayawati was Kanshi Ram's mistress is still under dispute.
I tend to think women had made if further in South Asian politics exactly because of the relatively lower status of women in society. It makes them less threatening to the existing social structure and could double as way to capture the women vote. So the dynastic women politician are perfect for this situation where they can cement the old political and social blocs of their father or husbands, not be a threat to the existing social order, and bring in the women vote all at the same time.