The Indian government only recognized autism in 2001. Till the 1980s, there were reports that the disorder didn't exist in India. Experts worldwide have estimated that 2-6 children out of every 1000 have autism. In India, currently, 10 million people are suffering.
Autism is a complex developmental disability which starts presenting itself in the first 3 years of a child's life. It is a result of a neurological disorder which affects the normal brain functions of a child, thus eventually affecting their communication (verbal as well as non-verbal) and social skills.
Keep in mind that different children behave differently due to autism; no two children will ever have the exact symptoms. Some may experience mild symptoms while others may experience severe ones.
Social skills: an autistic child will interact in a very different way. If the symptoms in the child are mild, then such people are socially clumsy and awkward, may pass comments which seem offensive to others and may or may not be out of sync with other people of their age group. For those suffering from severe symptoms, they show absolutely no interest in people whatsoever.