Your time horizon as mentioned----may be 3,5,7 for long term sip equity-----This is my perception.
In case you are looking anything below 5 years for investment in equity, it would be quite risky seeing the current market valuations. I would suggest that you go for more than 5 years in equity.
Anything below 5 years, you can go for debt funds.
But you need to be aware of the taxation implications and returns are not so aggressive as compared to equity. If you are a conservative investor with time horizon of less than 5 years i.e. looking for 2-3 years, you can go for equity savings fund. 5 years time horizon, you can take a call on balanced funds.
In case of 5-7 years, can go for multicap or diversified funds and 10 years in large cap funds and more than 12 -15 years in small and midcap funds. These funds are quite aggressive and returns also good. But all depends on market conditions.