Hello , Harish .

       Autonomous body in the sense the institute / college has its own acadamic calender . In that case the institute can take decisions of its own regarding the events , examinations , syllabus etc . 

      And if the college is not autonomous in the sense it is following some other institute for its events , syllabus etc . In this case the college have no freedom of its own .

     So now you could realise that autonomous institutes are far better .

 THANK YOU.