Hope it is an Indian origin good imported for repair and return purpose.
In this case at the time of import the fair market value of the product to be declared. Also, all import documents should clearly indicate the items imported is for repair and return purpose.
Duty need not be paid on these goods as per Customs notification no.:158 / 95 dt.:14.11.95. However, you have to execute a bond and BG.
After completing repair and export, the bond and BG executed @ customs shall be canceled. Identity of the cargo to be provided at the time of export.
Refer Customs notification no.:158 / 95 dt.:14.11.95 for detailed guidelines.