I think you are confused between provisions of co Act and provision of Income tax Act. First of all gross block is for the Provision of Income Tax Act & for Co. Act every assets is an separate assets. There is no gross block in co Act. For the purpose of Co. Act every assets should be booked in the a/c and after that it should be depreciated @ 100% if it is not more than Rs. 5000/-. And that assets should be shown in the books on a nominal value say Rs. 1. For the purpose of dep there is AS 6. But for the purpose of dep rate you have to refer the rate specified in the Co. Act. For the purpose of Income Tax assesse has to maintain a separate records of gross block of assets. And the dep. rate shall be apply on that assets as rate specified in the Income Tax Act.