Hello,
The Central Board of Secondary Education (CBSE) releases the previous year's question papers for Class 12th from this website : CBSE Class 12 Previous Year Question Papers With Solutions PDF Download
If you are referring to any other examination or board, please ask your question again with the name of the examination and board you are referring to.
Hope it helps !
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile