My son is 11months, 1 week he walks on his own and says mama but he is not intersted in pointing or clapping. should i be concerned about autism?

No: One of the earliest signs at this age would be lack of interaction with family members, and/or looking towards his parents for comfort.

A specific " mama": Used to get your attention, with smiles of delight when you look at him & say, yes, i'm mama!" is fantastic! acquiring words to label things is not the same as communicating. Pointing for what you want is a 12-month milestone, pointing to share interest in objects is 14-16 mos. Mimicking simple games like peek--boo, pat-a-cake & waving "bye" is his job now. Just show his doctor at his 12-mo check.