sir . right now i am doing m.sc in chemistry in distance education system . if i will qualify cat then i can get chance in IIM?

Yes, you definitely have good chance to get into IIMs. There is no problem about that. Also, IIMs gives weightage to non-engineers in order to promote diversity in their college.

After you give CAT exam then all the IIMs makes a merit list to call students for second round of interview and WSAT which is made in the basis of your aggregate score and which is based on different parameters such as MAT marks, 10th, 12th and graduation percentage, work experience, engineer or non-engineer, gender, extracurriculars etc. whose weightage vary according to different colleges.

In this being a non-engineer you also get extra marks in aggregate list plus generally, you can get calls from IIMs relatively at a little low CAT percentile. After getting a call you will need to go through the second round of interview and WSAT. Then again a final merit list is made including the marks of interview and WSAT to give admissions.

So, prepare hard and do well in CAT exam.
All the best!!