My 20 month old just starts crying when relatives try and get friendly with her, she doesnt play with other kids too,likes to do her own bit..how can i make her more social?

Like adults, there might be some babies who are naturally shy and introverted. I watched a Korean variety show with this introverted girl named Ji Un, who wouldn't interact with her peers and stayed at the back during classes. She eventually opened up after more sessions. Perhaps you could try to find a class which your baby is interested in as a start. Some babies take longer to open up, and it's perfectly fine. Don't force play dates on her, just let her interact with other children at her own pace. You'll be surprised. http://www.parents.com/kids/development/shy/raising-an-introvert/