What is the meaning of my names "Rusul" and "Raseel," and is it permissible to name a girl with them?

"Rasal" (with an open ra and sin) means a herd or a group of anything, and (with a kasra on the ra and a sukoon on the sin) it means milk. As for "Raseel," it means a correspondent, and it is also used to refer to a male camel (stud) that is sent to mate with females. It is permissible to name with both, but it is better to choose names with good meanings.