If all members of the family (your grandfather, uncle and father) were born in Palestine, then there is no direct pathway to British citizenship based on that alone. British citizenship by descent requires at least one ancestor in the recent past to have been born in the UK (as it is currently constituted).
I have answered a few other queries on Palestine and British rule there here
. Please read through them and get back to us with any further queries.
I am not a lawyer or immigration advisor. My statements/comments do not constitute legal advice. E&OE. Please do not PM me for advice.