NBFC

A non-banking financial company (NBFC) is a company registered under the Companies Act, 1956 and is engaged in the business of loans and advances, acquisition of shares/stock/bonds/debentures/securities issued by government or local authority or other securities of like marketable nature, leasing, hire-purchase, insurance business, chit business, but does not include any institution whose principal business is that of agriculture activity, industrial activity, sale/purchase/construction of immovable property.

So for a NBFC co is merely engaged in business of giving taking loans and advances for all corporates.

In your case merely investing in shares of subsidiary co does not fall under the NBFC head.because A non-banking institution which is a company and which has its principal business of receiving deposits under any scheme or arrangement or any other manner, or lending in any manner is also a non-banking financial company (residuary non-banking company).

and your comapany does not registered as a NBFC but as a traspotation co.

As per RBI Press Release dated 8th April 1999, if the financial assets of the company are more than 50% and income from financial assets if more than 50% of the gross income, then the company will be a NBFC.

So in your case, if the income from investment viz., dividend, interest income etc.  is kept less than 50% of its gross income it will not be NBFC.