Writ petition against municpalty

I had complaint to BMC (Bombay Municipal Corporation) about a unauthorized construction in my building where i am affected directly, But BMC is not taken any action since last 3 yrs , Now i want to file a writ of Mandanamus, can you please give your suggestions in this regard, Also please share if you have format for a Civil Writ Petition

Also should i go for a writ or a PIL

Thanks in advance