Yes, you can withdraw your money at any time from any scheme, except in the case of ELSS Tax Saving Schemes. ELSS schemes have a lock-in of 3 years from the date of investment.
There may be some charges and taxes levied by the Mutual Fund companies and the government respectively in case of redemptions based on the type of Mutual Funds and duration of the investment. You can read more about it here. We also show you details about the charges/taxes on the redemption page.
If you wish to check by when the redeemed amount will get credited to your bank account, refer to this FAQ.