Father not well - not sure what to do

Hi all

I need your help, I understand that immigration for family members is very hard due to tough immigration rules.
However my father is very sick for past 3-4 years and due to his health condition I spent around 14 months in india last year he recently visited me and every thing looks ok however again his heath is getting worst.

I am here on ILR and he is the only one in india as my only sister is in canada and my mother passed away 4 years ago.

I am not sure what should I do as Its hard for me now I am not sure I have read every where but can't fins any positive information which can support my case.

I would appreciate if any of the members can advise me.

Thanks.