I’m looking to invest 20k in a mutual fund for 2 months and expecting a return of 15%. Which funds should I opt for?

This depends on how many mutual funds you are holding. It does not make sense to invest in too many funds. About 5–6 should be good enough for most people. But as fund performances change, one can change the list over time. In your case given the smaller ticket sizes, about 2 to 3 separate funds would be an ideal solution.