Explanation:

In India's federal tax structure, revenue sources are divided between the Central and State Governments. Tax on Stamp Registration, commonly known as Stamp Duty, is primarily a source of revenue for State Governments, not the Central Government. This is because it is levied on property transactions and legal documents, which fall under state jurisdiction. Options (2) Tax on Commodities (like GST, which subsumed excise duty and sales tax), (3) Duty on Customs (levied on imports and exports), and (4) Tax Revenue on Income (Income Tax, Corporate Tax) are all significant sources of revenue for the Central Government. Therefore, (1) is the correct answer as it is not a Central Government revenue source.