Under new regime, no tax up to ₹12L net taxable income due to 87A rebate and ₹75K standard deduction. Effective tax-free salary: up to ₹12.75L. This excludes special-rate capital gains (equity STCG/LTCG), which remain taxable.
Old regime allows up to ₹2L home loan interest deduction under Section 24(b). If you pay significant interest, old regime may be better.
87A rebate reduces tax to zero if net taxable income ≤ ₹12L (new regime) or ≤ ₹5L (old regime). Max rebate: ₹60K (new) / ₹12.5K (old). The rebate applies only against tax on slab-rate income; it cannot reduce tax on equity STCG/LTCG.