Planning for intellectually disabled siblings

I wanted to understand how do I plan for my intellectually disabled sibling? I know my sibling will be dependent on me for the rest of their life. How do you plan this financially? Worst case scenarios well?

Does India provide any social support? I heard foreign countries have a lot of special programs ex. Special trusts, assisted living facilities, social aid etc.

I want to know from people who have planned and built their life around this.