Defamation at work place

I am working in my company as cost consultant. in past couple of months, in regular interval of time, i was mentally harrashed by one staff from client. recently I felt he crossed limit when he publically stated that i have been bribed from contractor. however not only my senior but his seniors also do know me very well. also it is to be noted that he has already been given 1 time warning letter from his management for his conduct. i am not sure that he is treating us in harrasing manner either to demonstrate his activeness or with mentality of range or with any ego or any other reason. instead of maintaining professional ethics, if someone exploiting work environment can be taken into account under IPC act or not? in the case if senior is found knowing all incident and even supporting him with clear cut decision that they are client and they are in touch with well reputed lawyer in Mumbai graduated from US and tget also believe that their management will alwaus listen to what they report as there is no direct communication. also project director not taking any action as the fellow is permanent employee. DSR 2016 has been issued by CPWD. if someone schallenges that all item in this code is wrong. however all legal departments, all government bodies accepts it. this code freezes fractions of analysis and have suggested to check market rate of items with support of at least 3 Quotes. can I ask his to lay down his opinion and my opinion in written and apply for RTI to CPWD??