Eating undercooked rice will not harm you so it's safe to eat undercooked rice.
However undercooked rice will be harder to chew and digest so it's best to fully cook the rice for a better experience when eating the rice.
I've tried eating undercooked rice and it was just too hard to eat and chew so I decided to cook it longer and it tasted better and I was able to eat it easier after it being fully cooked.