Senthil Bro, no extra coaching is required. Just stick to Institute Study material. This is my personal experience.
For Comml & Indl Laws Paper paper, you may check following analysis by me:
Contract Act, Sale of Goods Act and Factories Act among themselves have been giving 28 to 46 marks out of 50 allotted for Commercial and Industrial laws. The other 50 marks are for Audit, as we all know. The other laws - Industrial Disputes, workmen Compensation, Payment of Wages, Minimum Wages EPF, Bonus, Gratuity, Consumer Protection, LLP, RTI, Competition Act and NI Act have been giving 30 marks on an average. Hence, my personal opinion is that Contract Act, Sale of Goods Act and Factories Act are the Gold Mine of marks for this paper. However, one big IF is there - We are sure of these 28 to 46 marks from these chapters if and only if - WE HAVE EXTRA ORDINARY UNDERSTANDING of these three chapters. These three chapters and Vouching/Verification and Management Audit from the Audit section should give us marks above 60 and EXEMPTION. I am not for selective study and hence, since enough time is still there, we should have grasp of all the given laws, may be skipping the Minimum wages, Bonus, LLP and RTI act which have been giving only 2 marks on an average. Hope this analysis is useful.