A 3 years old boy with normal developmental milestones with delayed speech, has difficulty in communication and concentration. He is not making friends. Most probable diagnosis is:

The given scenario where child is having delayed speech and difficulty in communication and concentration and is not making friends, suggests - Autistic spectrum disorder. Autistic disorder: qualitative impairment of social behaviour impairment of communication skills stereotypic & restricted behaviour onset before 3 years. More common in boys