If a court has passed a decree for specific performance directing execution of a sale deed, and you purchased the same property from the original seller either before or during the litigation without knowledge of the dispute, you may have grounds to challenge or resist enforcement of that decree against you — though your position depends heavily on the timing of your purchase and what notice you had of the earlier agreement. Under Section 19 of the Specific Relief Act, 1963, specific performance of a contract can be enforced against a subsequent purchaser of the property, except where that purchaser bought it for valuable consideration and without notice of the original contract or the pending suit, making the question of "notice" absolutely central to a third party's ability to resist the decree.

If you purchased the property while the specific performance suit was already pending, the doctrine of lis pendens under Section 52 of the Transfer of Property Act, 1882, generally binds you to the outcome of that suit regardless of whether you had actual knowledge of it, since the law treats the pendency of a properly filed suit as constructive notice to the world — this significantly limits your ability to challenge a specific performance decree simply on the basis that you personally didn't know about the earlier agreement, if the suit was already filed at the time of your purchase.

If, however, you purchased the property before the specific performance suit was filed, and you can demonstrate that you paid valuable consideration and had no actual or constructive notice of the prior agreement to sell — meaning you conducted reasonable due diligence, such as checking for existing agreements, encumbrances, or any indication of a prior sale commitment, and found none — you may have a genuine defence under the proviso to Section 19 of the Specific Relief Act, 1963, and can potentially resist enforcement of the specific performance decree against your purchased interest.

To assert this defence, the appropriate step is typically to seek impleadment in the specific performance suit itself if it's still pending, or, if a decree has already been passed, to challenge its execution against you through objections filed under Order 21 Rule 97 to 103 CPC, specifically contesting that you are a bona fide purchaser without notice and therefore not bound by the decree.

Given how much your position depends on the precise timeline of your purchase relative to the original agreement and the suit, and on demonstrating genuine, reasonable due diligence at the time you bought the property, careful documentation and legal assessment are essential. For representation before Ahmedabad's courts, the Top Property Lawyers in Ahmedabad | Aapka Legal Advice directory can connect you with suitable counsel, and our legal experts at Aapka Legal Advice can help assess whether you qualify as a bona fide purchaser without notice.

In conclusion, a decree for specific performance can potentially be challenged by a third party purchaser in Ahmedabad, but only where that purchaser bought the property for valuable consideration and genuinely without notice of the prior agreement, under the proviso to Section 19 of the Specific Relief Act, 1963 — purchasers who bought during the pendency of the suit are generally bound under the doctrine of lis pendens regardless of actual knowledge.