Registered employees union could be give affiliation

Dear Senior,
You are requested to please advice that registered employees school union of city could be give affiliation to unregistered individual school union. Please clear legalities of same as per act & rule.

Dear VKS,
Your query is not clear to me. In sum and substance, whether you want to know about affiliation of an unregistered Trade Union to a Federation of Trade Unions with ideological unity OR about the recognition of an unregistered Trade Union by the employer of an organization where the union functions.

Yes, Sir- I want to about affiliation of an unregistered Trade Union to a Federation of Trade Unions with ideological unity ..

Trade union may not be recognised by employer, but the Federation of trade unions can give membership as per their rules

Dear VKS,
I think that Central Trade Union Organizations or Federations would consider registered trade unions only for the purpose of granting affiliation. Kindly check with the Federation of your choice.

Dear Mr Uma,
My reply was based on this link https://www.intuc.net/index.php?articleid=6
It does not bother whether employer has been recognised or not.
Sometimes employers refuse to recognise unions for some reason or other.

Dear Mr.Rao,
The cryptical fashion of framing of questions some times tempt us to give answers other than what exactly sought for. That's why I raised some queries in my first reply and the poster also responded affirming the question he actually intended. Since the affiliation of any union to a Federation of trade unions with ideological unity is a simple and formal transaction between the centralised and individual association of employees so as to enhance the power of bargaining of the latter, registration of the trade union under the Trade Unions Act,1926 or under any other Act like the Societies Registration Act,1860 would be the only precondition. The link you've cited confirms this for which I should certainly thank you. As rightly observed by you, recognition of the individual union by the employer or not is not at all an issue in the process of affiliation.