Step 1: Puddling is a tillage operation done in wet soil for paddy cultivation.
Step 2: The main purpose of puddling is to reduce percolation loss and create a soft puddled layer suitable for rice transplanting.
Step 3: A rotavator cuts, mixes, and churns the soil effectively under wet field conditions.
Step 4: Therefore, a tractor with rotavator is best suited for puddling operation in paddy.
\[
\boxed{\text{Tractor with rotavator}}
\]