1. You can switch to Direct Plan from Regular Plan. But please remember that even in such switching, you have to pay the applicable exit load, if any.
2. Further, you may also note that in such switching also, the tax rule would be applicable. This means, if you switch before one year in case of an equity fund, then you are liable to pay tax. In case of a debt fund, for availing tax benefit by indexation, you are required to switch after three years.
3. Further, your father has opted for the Systematic Withdrawal Plan (SWP) in respect of Regular Plan. Direct Plan is treated as a separate scheme. So, after switching from Regular plan to Direct plan, you have to again opt for new SWP. Old SWP applicable for Regular Plan will become invalid.
"If you are killed in action, you go to Heaven. If you win, you rule this Earth (as beautiful as Heaven). That is why, O son of Kunti, take a firm resolve and fight!"-- Shrimad Bhagwad Gita