I scored 6.8. Cgpa on class X and 57% in class XII. Now persuing B.A. Is there any chance of getting admission into an IIM?

Since you have average academics and no work experience, you would need minimum of 99.5 percentile in CAT ro receive call from IIMs and need to give wonderful GDPI to get admission.
You need to work hard, Join coachibg Institute lkke TIME, CPLC, Careerlauncher, IMS.
The key to success is practice with mock exams, atleast 20 mock exams are must.
You can refer to books like Arun Sharma, Nishit Sinha, for quants and data Interpretation.
For Verbal ability and Logical Reasoning go with Ajay Singh.
All the Best.