I would strongly recommend you to add one hybrid or balanced fund to your portfolio like HDFC Prudence or HDFC balanced fund
The funds smartly invest more in equity when markets are down and move most of the money to debt when markets are at high.
You will ensure some debt component into your portfolio by investing into it.
so you should have 4 funds maximum u can invest int o 8 diversifiction above that is nothing but management overhead and more charges to the fund managers
when u can achieve same result by smart choice of funds not more than 8