As mentioned on this website, the type of capital gains will depend on the duration for which the mutual fund is held for -
Once you invest in a Mutual Fund scheme, any change you wish to make in terms of changing plans (Regular/Direct), options (Growth/Dividend) or changing schemes within the same fund house will be considered as a sale (redemption). Hence making any such change is possible but like redemption, these changes will attract exit load and capital gains tax depending on how long you have been invested.
Other than that, the type of capital gains also varies based on the nature of the mutual fund (aka debt or equity). This thread talks about that in more detail for debt mutual funds -
For equity mutual funds, this concept is explained in detail in this blog post by @Quicko -
Equity Mutual Funds – Since these mutual funds invest in equity-oriented instruments, the treatment is the same as equity shares.
Long Term Capital Gain (LTCG): Any gain arising on the sale of equity mutual fund held for more than 12 months is considered as Long Term Capital Gain i.e. LTCG on mutual funds.
Short Term Capital Gain (STCG): Any gain arising on the sale of equity mutual fund held for less than 12 months is considered as Short Term Capital Gain i.e. STCG on mutual funds.
If you are interested, the Taxation for Investors chapter on Varsity explains these concepts in much more details (including how mutuals funds are categorized into equity or debt category)