When a new cat arrived in our household where other cats were already residing, I'd give all cats a bath with warm water, using a small amount of baby shampoo, and rinsing thoroughly. Then they'd all have the same body odor and the old cats accepted the new cats.
Occasionally adult males will eat kittens, so your male cat might think those little kittens are prey; perhaps keeping them separate until the kittens are quite a bit larger would be best.
My neutered tomcat has always been very patient with kittens (the keyword here is “neutered”).