Pin Code of Tiyan BO is 841231, SIWAN, Bihar May 20, 2020November 25, 2019 by Sarkari Help Advertisements 0 (0) Information about the post office and pincode of Tiyan BO, SIWAN, Bihar Tiyan BO Pin Code : 841231 The Pincode 841231 of Tiyan BO represents Siwan Division post office in SIWAN revenue district which comes under the Bihar Circleof Muzaffarpur Region. How useful was this post? Click on a star to rate it! Submit Rating Average rating 0 / 5. Vote count: 0 No votes so far! Be the first to rate this post.