We are an Italian independent art group and we want to adopt one of Mr. George's books into a screenplay, And we want to make a film based on that. What should we do to get Mr. George's permission?
The grammar isn't wrong, but some words that shouldn't be are capitalized within sentences. I think the word "adapt" might fit better than "adopt". The first sentence is a little rambling with three independent clauses. I suggest some changes:
We are an Italian independent art group, and we want to adapt one of Mr. McDonagh's plays into a screenplay to make a short film. What should we do to get Mr. McDonagh's permission?