Even in a decentralized organization, there will be some policies that are common and some that are locally applicable. For instance, if you have offices in Mumbai and Bangalore, and Bangalore has a factory, the Factories Act, Shops and Establishment Act, and labor policies will apply as per Karnataka state. The same applies to holidays. However, employee leave, recruitment policy, annual rewards, or performance appraisal system will be common across the organization, irrespective of the location. Dearness Allowance (DA) may be common, but House Rent Allowance (HRA) and City Compensatory Allowance (CCA) may vary according to the local cost of living. Therefore, you should be able to segregate both and implement accordingly. Some HR policies are administrative in nature, and you should be able to differentiate between the two. Best wishes.