If you are talking about offline sample papers then i cant help you with that but if are searching for NATA sample papers online then i can suggest you a process.
Go to google.com
Coick on the search bar and type NATA model/ sample papers.
You will get many websites like " tcyonline " and "blog.oureducation" and "aptoinn"
They will provide you with enough sample questions with their answers.