LTCG ON MF Investments

Please validate the following statement.
"Many MF investors think that if they don’t withdraw before March, they have to pay taxes on their return on their investments. This is not true. Even if your gains are more that Rs 1 lakh on the mf investments that you made before January 31 st , 2018, you will not pay any tax on them. The new rule will be applicable only on investments made after January 31,”