The study aimsto compare the effect of Functional Communication Training, Sensory Integration Therapy and Behaviour Interventions for Challenging behaviours in children with autism.A total of sixty (N=60) children diagnosed with autism spectrum disorder exhibiting challenging behaviors were recruited for the study through convenience sampling. Amongst these, twenty (n=20) children were randomly assigned in one of the three groups (Functional communication training, sensory integration therapy &behavioural intervention). Functional behavioural analysis (FBA) and Repetitive behavior scale- Revised (RBS-R) were the outcome measures selected for pre and posttest analysis. The current study results showed that there was a clinically significant difference between the post test scores of the three groups (Mean value: BI 19.50, SIT 20, FCT 23), BI successfully reduced the frequency and occurrence of challenging behaviours significantly as compared to the other two groups.