What will happen if rent is not paid for a few months ?

Hi all one of my friend is living in a nestaway property and she has not paid the rent for almost 8 months but she has paid the other charges to the landlord like electricity and maintainance she has not even signed any agreement and now the company people are telling her that they will file a FIR against her. She has not paid the rent because she was ill and she doesnt have a job which has been communicate to the company. Could you please tell me the consequences of what will happen if she leaves the property without informing any one and can the company file an FIR against her in absence of a written agreement.