mutual fund

You will have to redeem the earlier units, and purchase new direct plan units. 

All the mutual funds schemes have both the options, Regular & Direct ...

I would recommend you to invest in HDFC's mutual funds. I have friends who have been investing for a long time and suggested HDFC mutual funds. Hence, I started investing in HDFC three years ago. As you want to know about direct plans in mutual funds, HDFC equity savings funds are very profitable of all HDFC mutual fund. It is the best hybrid mutual funds available and has a direct plan available. This fund has been performing really well and earned a 6.5% returns in the last year. There is HDFC short-term plan mutual funds which are another option with a direct plan and gave returns of 6.34% last year. It is a debt mutual funds with good performance and easy liquidity. HDFC long term advantage fund allows a minimum investment of INR 500 with a direct plan and is the best equity mutual fund in India. I hope this was helpful and you are able to choose one of these plans for good returns in the future.