14 April 2012
First, it depends on whether its an equity fund, debt fund or a gold fund in which you are doing SIP.
If its Equity Fund, then hold it for more than 12 months and you wont be required to pay any CG tax.
If its a debt or Gold Fund, then holding it for more than one year would require you to pay LTCG which would be 10% of gains without indexation or 20% of gains with indexation.
In any case, it is advisable to hold for more than one year.