Please find below the answers to your queries in seriatim:
1. How many people are required to go on strike? The Trade Union Act, 1926, doesn't contain any provision fixing the minimum number of persons who can call for a strike. The persons employed in public utility services are not allowed to go on strike in breach of their contract.
2. How many people are required to form a trade union? Any seven or more members of a trade union may, by subscribing their names to the rules of the trade union and by otherwise complying with the provisions of this Act, apply for registration of the trade union.
3. Where to get the trade union registered? The appropriate government appoints a Registrar of Trade Unions for each state. Additionally, the government appoints Additional and Deputy Registrars of Trade Unions for the purpose of exercising and discharging such powers and functions of the Registrar under this Act within their local limits.
Regards,
BS Kalsi