Bathroom seepage emanating from the flat above is a prevalent issue in apartment buildings, leading to damage in the lower flat and potentially resulting in health concerns. Such seepage can result from leakages due to poor material quality, incorrect installation, or lack of maintenance. Regular inspections and maintenance of the plumbing system in the upper flat can mitigate such problems.

If the resident of the upper flat is uncooperative in addressing the issue, several legal measures can be taken:

1. 
   Legal Notice: A notice can be sent to the resident of the upper flat, demanding the cessation of the leakage and appropriate repairs. Compensation for damages can also be claimed.
2. 
   Society Intervention: A complaint can be lodged with the apartment's society. The society has the responsibility of ensuring the maintenance of common areas and addressing nuisances caused by any members.
3. 
   Local Authorities: Reporting the problem to the local municipal corporation or development authority can be effective. These bodies are tasked with enforcing building regulations.
4. 
   Consumer Forum: Victims can approach the district consumer forum under the Consumer Protection Act, 2019, arguing that the upper flat owner's negligence is an unfair trade practice.
5. 
   Civil Suit: A lawsuit can be filed claiming that the upper flat owner's negligence has significantly interfered with the use of the property in the lower flat, seeking injunctions and damages.

It is essential to address such issues promptly to avoid escalating damage and health risks.

If no action is taken complain to muncipal corporation against flat owner refusing to rectify leakages 

2) you can file complaint before cooperative court and seek orders to direct flat owner to rectify leakages 

you will have to file a police complaint for nuisance and annoyance 

Please note that the whats app group is not a legal platform where you can raise a complaint and seek an action on the basis of such complaints.

If you were aggrieved by the lethargic attitude of the society, nothing prevents you to issue a legal notice to the neighbor demanding him to rectify the fault immediately failing which You can proceed with a complaint to the deputy registrar of cooperative societies o approach the cooperative court  to seek direction to the concerned neighbor to repair and make things straight

- Since, the society not taking any action against him , then you can send a legal notice to the said owner of the flat and also to the society 

- Further , if society is not giving attention , then you can also approach eh registrar of the society as well  against the society.