Indian Passport with ILR lost in India

Dear Members,

I need some serious help...The situation is as follows:

1. My parents has UK ILR back in 2005 on Indian passport. They have regularly stayed with me in the UK.
2. But currently they are visiting India. Unfortunately they have lost their passports.

Currently they are in the process of getting a new Indian passport. But what I need to know is that how can I get the ILR stamped?

Do they need to apply it in India's UK embassy? Can someone please let me know the process? Their return tickets are in October this year. Is it possible to get the ILR stamped before that?

I am really concerned with the situation. Any help on this will be appreciated.

Thanks in advance.

Nirav