My 6 years old have difficulties in building frienship . any suggestion please?

Answer 1

I wouldnt worry about a 6 yr old making friends. He/she is still a baby for god's sake.

Answer 2

There could be several reasons for that one is shyness. If he/she is shy it's OK they'll shake it off the older they get.
Another reason is fear. Some younger kids just fear friendship with other kids because of fear that they won't like them back. but one thing that might help is talking to your son/daughter and tring to find out what's wrong.