@Sambhav Jain Why complicate. Here is simple calculation for your ready reference.
Other Income is Rs. 3 L and STCG is Rs. 4 L plus you do Rs. 1.5L investment under 80C.
Under Old regime,
Taxable income will be Rs. 5 L after considering std deduction of Rs. 50,000 and deduction under 80C of Rs. 1.5L
Tax on other income will be NIL, However,
Tax on STCG will be 15% x Rs. 4 L i.e. Rs. 60,000/- which after 87A rebate of Rs. 12,500/- will become Rs.47,500/- or Rs.49,400 with 4% cess
Please note that you can not take set off on STCG as the income is more than Rs.2.5L
Under New regime,
Taxable income will be Rs. 6.5 L after considering std deduction of Rs. 50,000 and no other deduction applicable.
Tax on other income will be NIL, However,
Tax on STCG will be 15% x Rs. 4 L i.e. Rs. 60,000/- which after 87A rebate of Rs. 25,000/- will become Rs.35,000/- or Rs.36,400 with 4% cess.
Please note that, under 87A rebate of Rs.25,000 is available under new tax regime if total income is upto Rs. 7L
Hope, it clarifies now.