Location Change—Urgent, Need Help!!

Hello everyone. I will be joining Accenture this Friday and my assigned location is far away from my home location.
I have few questions, if anyone would be kind enough to answer them:

1. Is there any possibility to change my location from my assigned base location to somewhere nearer to my home location? I live in Tier-1 city.
2. Also, can I work from the office in my hometown other than the assigned base location? Is it possible?

I talked to HR and my onboarding POC for both of these and they basically said NO.

And just a little FYI— I am not asking this on a whim, I have a very legitimate reason for this. My mother has a heart problem and I am her sole caretaker. I even have a written letter from the doctor from a well known hospital stating explicitly that I need to be there with my mother to take care of her.

PS- I’m not a fresher. Joining at L10 position.