A field study on development of package of practices for mechanized transplanting in rice was conducted at Tamil Nadu Rice Research Institute, Aduthurai during 2020-21. Six treatments viz., two age of seedling 15,21 days old seedlings, two time of planting viz., normal, and 15 days delayed planting, It was also compared with conventional transplanting with 25 days old seedling under normal and 15 days delayed time in randomized block design. Mat nursery was prepared for 8 row Yanmar transplanting machine. The result showed that mechanized transplanting with 15 days old seedling under normal planting of June planting recorded higher number of tillers (355/m2), No. of grains/panicle (162/panicle) and grain yield (5511 kg/ha) during normal time of planting. Delayed transplanting with 15 days resulted in decrease in grain yield. Delayed transplanting of rice beyond June 30th recorded reduction in yield varied from 361 to 1001 kg/ha. Higher net income (54506 ₹/ha ) and B:C ratio (2.2) was recorded in 15 days old seedling under mechanized transplanting under normal planting time of June.