A flexi cap mutual fund is a mutual fund that would by
mandate need to invest a minimum of 65% into equity at all times.
The remaining 35% can either be invested in debt,
international equity, cash or any of the above caps or all.
This 65% is only minimum which can even go up to
100% in case the fund manager so desires.
Whatever the allocation is between 65% to 100%,
there is no restriction with relation to large cap, mid cap or small cap
stocks.
Basically, the fund would be run as how erstwhile multicap
mutual funds were being run.