Step 1: Understand the reform being described.
An automatic property mutation system updates land ownership records on its own after a sale or transfer, cutting down delays.
Step 2: Eliminate the other states.
Rajasthan, Mizoram and Assam have their own land record initiatives but did not introduce this specific automatic mutation system in February 2026.
Step 3: Recall the actual state.
Karnataka introduced this automatic property mutation system, improving transparency in its land and property transaction records.
\[ \boxed{\text{Karnataka}} \]