SIPs are meant to be for long term investment. If the markets have fallen and your fund has fallen along with them, then it is not a sufficient reason to exit the fund. You may suffer from exit load unnecessarily.
If the fund is underperforming its peers, then you should put the fund under watch and see how it shapes up over the next 3–6 months. Abruptly quitting a fund is not a good idea. It is like pulling out a plant and trying to plant it elsewhere.
You should consider increasing your investment int he fund in a corrected market, provided the fund is a good one. For best funds, you can check out jama.co.in and the Picks section.
Please see my answer here: What should I do if my mutual fund is under performing?
