Comment on Taxation Simplified
Tax calculator is available on the income tax site: http://law.incometaxindia.gov.in/DIT/Xtras/taxcalc.aspxIn
Case1: You have capital gain of 4lks and Short term capital gains of Rs 20lks. Short term capital gains are taxed @15% and the 4lks will be taxed as per normal tax calculation. So net tax will be around 3lks.
Case 2: Since your profit of 20lks is on shares held for more than 1 year, it becomes long term capital gain, this is exempt from taxes. You will have to pay tax only on your 4lks salary, which based on the calculator will be around 20k.
Case 3: Since there is no other income, you have to pay short term capital gain on 20lks