Dear Rupali,
Long back since I served as an Additional Controller of Legal Metrology in Tamilnadu. Lots of changes have occurred since then and as such I am not aware of the exact procedural formalities obtaining now in various States. As far as I know, as a user of wgts and measrs, you have to get reverified and stamped all the electronic weighing and measuring instruments and higher denomination instruments such as platform scales once in a year and all other items once in two years. If you sell your products in packaged form, you have to obtain a licence in this regard, your packages should be only in the denominations prescribed in the Packaged Commodities Rules in force, should contain certain statutory declarations such as name of the commodity, its net contents, maximum sale price, date of expiry in case of perishable goods, name and address of the manufacturer/packer, e-mail id, customer care contact no and the like. If you are a manufacturer of weighing and measuring instruments, you have to obtain a licence from the Director of Legal Metrology and get your models approved before hand. Better consult your area Inspector of Legal Metrology or State Controller of Legal Metrology for the current procedures and exemptions if any.