Short term capital gains

You have not mentioned whether you are looking at equity or non-equity funds.

In simple terms, for every single investment (lumpsum or SIP) in equity mutual fund schemes, you do not pay tax if the holding period of the units is greater than a year. You have to pay 15 per cent of your profits (short term capital gains) towards tax if your holding period is less than a year.
For every single investment (lumpsum or SIP) in non-equity fund, taxes are applicable according to your tax bracket after adding the gains to your income if the holding period of the units is less than 36 months or three years. If the holding period is greater than three years, you would pay capital gains at 20 per cent with indexation benefit.