I have invested in one MF(Tax saver growth) where the NAV was 208. Current NAV is 154.Will it be a loss?

I invested in 2007. By the beginning of next year, 3 years will be completed. With the current NAV, it will be a loss. My question is can I switch this units to some best performing funds after 3 years? If so, how to do this? Can anyone give information about which funds to go for and what are the things to be taken care?