Need Guidance on Maintenance and Divorce

Hello sir. I am Sandeep. I have been married since May 2007. We were together for almost 16 years. I was attracted towards a girl from my office and was involved in physical relationship with my fellow colleague. I had confessed that and since then we have not been in good terms and have been falling apart emotionally and physically. We all used to stay together with my parents however, due to my actions, the family was disturbed and She left me in February 2024 and started staying separate. I am father of two kids, a 16 yrs son and other son is 13 yrs old. From past 7 months, we are staying separate. She had taken my kids with her and currently they stay with her. During the time when I had confessed about my actions with my office colleague, I had also asked her to look for separation, if she doesn't want to stay together however, we never spoke about it earlier. I was hoping that, things will be normalized between us however, we could never get back in good terms since the last three years. Today, 25th September 2024, she sent me a notice seeking maintenance payment of 120,000 INR per month. We own a 2 BHK house at the outskirts of Pune and although, I have been paying EMIs of this house since start, she has been the co-applicant in the house loan leading to a jointly holding this residence at the moment. Since the time, she has started staying separately, I have been taking care of all the necessary expenses such as monthly groceries, kids' educational and all other expenses such as clothing, haircut and other sundry expenses etc... and also been paying 7,500 per month. I don't stay with my parents and they stay alone as I working from a different city. I also have to incur expenses for my stay in different city (~30k per month) and expenses for my parents who are staying with me and the expenses of my house (~ 30k per month). I also pay for the insurance of my kids, wife and parents. My current salary is 25LPA and she also has a garment business in a rented shop with a net earning of ~15k per month Need help to understand: 1) if she goes in court for maintenance how much she can claim.? 2) if she goes for divorce, how much she can claim on my house property.? 4) if she files maintenance case against me, how much do I need to give it to my son as a maintenance? Will it be on sharing basis? 4) right now she is not living with us from past 7 months, so what is legal way to go for divorce so, I do not have to give more money