Under Indian law (Transfer of Property Act), when there is no written lease agreement but rent is accepted monthly, it is legally treated as a month-to-month tenancy. This can be terminated by either party by serving a 15-day prior notice.
Since there is no written contract authorizing her to renovate or stating that the landlord will reimburse her, she cannot legally demand this money. Legally, any permanent alterations made without the landlord's explicit written consent are considered unauthorized.
Preventing the landlord from accessing electricity meters (especially when they control the supply for the whole building) is a violation of the basic landlord-tenant relationship. It poses a safety hazard and disrupts other tenants.
The security advance is always refunded at the time of vacating and handing over the keys, after deducting any unpaid bills or damages. Never pay it upfront, or she may pocket the money and refuse to leave.
Do not rely on verbal conversations anymore. you can send a whatsApp/Email, Send a polite but firm message summarizing past events. You can state that you requested here to vacate the premises. .You can also state that regarding her request for renovation expenses, you never authorized any structural changes or agreed to reimburse any costs. Furthermore, you require immediate access to the ground floor utility space to check the electricity meters for the other floors. Please let us know a time today when you can open the lock." If she responds aggressively or denies access, you have written proof of her non-cooperation.
Subsequently need to send a formal Legal Notice for Eviction through a lawyer instructing her to vacate the premises within 15 days.
If she shouts at your mother-in-law, threatens you with false cases or creates a nuisance for other tenants, you may lodge a complaint with the local police station for criminal intimidation and creating a public nuisance. The police usually do not interfere in landlord-tenant civil disputes, but they will intervene if there is a law-and-order issue, harassment of a senior citizen (your mother-in-law), or public nuisance to neighbors.
Your immediate next step should be to consult a local civil lawyer who specializes in rent control and property disputes. Do not let her profession intimidate you, the law applies equally to lawyers, and courts look very unfavorably on advocates who abuse their knowledge to harass landlords.