baby kitty food

Sorry if this is a silly question but it's my first time with kittens.

My 4 six week old kittens are in the process of starting to eat solids. The only thing they like is canned tuna. I have started to mix it with Royal Canin babykitten food..they won't eat the moistened or dry kibble on its own.

I'll try raw chicken tomorrow. But my question is whether its ok to feed them canned tuna?

Dry Kibble I think is to much for the little teeth. Is it moistened if so add tuna to it or the juice.