"To work in an organisation providing ample scope for growth." or
"To work with an organisation providing ample scope for growth."
Which one is correct.
If you want to be an employee, then use "in."
If you want to be a consultant, then use "with."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.