Put on a 30-day review track during probation. Need senior advice on voluntary exit and track survival.

Hi everyone, seeking some raw, tactical advice from seniors who have survived the Indian IT service/vendor matrix.

Context:

• 4 YOE React Developer.
• Joined a mid-tier service-based MNC 3 months ago. Currently on my 6-month probation.
• Deployed to a foreign client.
• I have 6 months of emergency savings, so I am not desperate for immediate cash.

The Incident:
The client manager escalated me to my parent company's HR, stating that my code quality and implementations are not up to the project standards.

HR sent a formal 30-day review track email. The email explicitly states: "If the required improvement is not demonstrated during this period, 30 days from now will be your Last Working Day."

The Notice Period is 60 days on Probation.

My Questions for the Community:

1. Survival: Is it actually possible to survive a 30-day track when the client manager has already escalated to the parent company? Or is the decision to fire me already made?
2. Best Damage Control: Is submitting a voluntary exit notice immediately the absolute best move to protect my background verification (BGV) record?
3. Validity Under the Track: If I submit my voluntary exit notice now, can HR reject it or say, "The review track has already started, so it's too late and you can't leave now"?

Appreciate any blunt, honest insights from people who have been through this.