Hi! Thanks for the question!
Your neighbour is responsible for the same. If the leakage was caused with him having the knowledge of the same he can be prosecuted for mischief.
1.Your neighbour can be prosecuted and punished for committing the mischief of damaging your property. If the police does not initiate his prosecution then you can file the criminal case directly in the court. Before that you are adviced to file a complaint in the Municipality first and inform the police too.
2.If the Municipality does not help, you can also file a lawsuit for damages against your neighbour to recover the cost to be incurred on the repairs and also compensation. The fate of the case shall depend on how well your lawyer convinces the court.
you need to establish the cause of the leak. This is important as it will help determine who should be responsible for putting things right. In most cases the critical piece of information is identifying where the leak started.
If interested, please get in touch. We will be ready to assist you to protect your legitimate rights and to legally force a misbehaving upper floor tenant/owner/society membeer to respect rights of his neighbours.
Adv Ibrahim Deshmukh
202 Hamza Residency
Bandar Road, Near Panvel City Court
Panvel 410206 New Mumbai