How to file defamation case

Hi All,

   I am a peacefull owner of an Apartment in Andhra Pradesh. However, i don't stay in that apartment as my job location is in Hyderabad (Telangana State). 

Flat Resident Owner Association is being formed and got it Registered for our 35 apartments community. There are no BYE LAWS as per my knowledge ( even when i ask for bye-laws none of the association body cares ). Executive body is formed as per mutually agreed by few owners without having any bye-laws procedures. Since the last couple of years after formation of the association body with president, secretary, and treasurer, I am being harassed by secretary for unknown reasons to name few such as no invitation for meetings, warning my tenants not to use common areas, not giving receipts for the maintenance amount paid etc. I dont know what is the intention of secretary for harassing me nor he will answer when i tried to call him ( same will happen when i try to complaint to executive body)

I was niether invited for many of the association meetings nor invite for few meetings now and then with a very very short notice ( so that i will not attend). The same has been referred to the president  and few co-owners of the association but president keeps dumb ears and co-owners feels why to involve and they keeps quite.

Secretary is also causing inconvenience to my tenants staying in my apartment hence tenants are vacating my flat very frequently this information has come to my notice recently when a new tenant joined my flat. I also came to know from the same tenent and one person outside of my apartments that secretary is telling wrongly about my character like passing oral comments to co owners and my tenent that i am not good person / will never attend meetings / will cause nuisance etc.. 

Since i am non-local to that place, secretary is taking that liberty and defaming me a lot by passing bad comments on my character. 

Can someone please help me whether i can file a defamation case in such case and i doubt on the below points :

• Though it is apparent that secretary is passing indecent comments about me in the apartment community, i doubt when i request the same people     (my new tenents and person outside my apartment community ) who told me about this information will come forward when i try to prove that case may be because those people might be of fear of issues from association body if they tell something about them in public.
• Though the fact remains real that secretary is commenting such filthy statement against me and If i cant prove them may be because of non local status can i  still file a defamation case? If so how to handle in proving those facts. ( Since secretary is deliberately causing incomvience and none of the association body nor co owners in that apartment is supporting me (as a non local)  i am totally disturbed and also it is causing me financial losses as my flat is getting vacated frequently and no new joinee are coming because of such false propaganda from secretary) 

Somebody please help me and guide me ... i am sorry if i am not able to present my issue clearly.

Thanks 

Ramakanth