Written abuse on whatsapp

Lawyer who is president of my society keeps garbage bins near my carpark. Rats come into my carpark. I do not have proof of it. Earlier it was kept near diesel generator but since the mechanic told the society to keep bins away from generator since rats may damage wiring, it is not kept near diesel generator. I told the lawyer to keep it near main gate and not near anybody's carpark similar to other societies but he does not agree. Other members of the society agree with lawyer, not me. I got irritated and called the lawyer an idiot, rogue, rascal on whatsapp so he has proof against me. So far no police complaint has been filed against me even after a week. If he files a police complaint will I be prosecuted under SC/ST act? Earlier he threatened to evict me from society also and called me a nuisance and troublemaker. I do not have proof of this since it was verbal. What is the maximum punishment for me in both a civil and criminal case filed by lawyer against me? What is the maximum time limit for filing a police FIR against me ?