The gains will be at flat 12.5% without indexation (Fy2024-25)
see this, my old topic
Has Debt Mutual Funds been nuked by Budget 2024 - General - Trading Q&A by Zerodha - All your queries on trading and markets answered
For FY2025-26, there is minor changes to how ltcg/stcg is classified. post #30. only for units sold after 1-apr–2025
also, stcg has benefit of rebate, while special rate tax/capital gains have only basic exemption limit benefit.