Following is the definition of control as per AS-21:
“Control:
(a)the ownership, directly or indirectly through subsidiary(ies), of more than one-half of the voting power of an enterprise; or
(b)control of the composition of the board of directors in the case of a company or of the composition of the corresponding governing body in case of any other enterprise so as to obtain economic benefits from its activities.
'Subsidiary' is an enterprise that is controlled by another enterprise (known as the parent).
So its either shareholding of more than 50% or composition on Board. Hence, in order to be a subsidiary it can be through shareholding or control through Board.
And there might be cases where funds have been received (by the investee co. towards share allotment) but shares haven't been alloted, but given that directors exercise control, it will satisfy the condition (b) and the investee co. will have to be considered as a subsidiary.
You could also refer ASI-24 regarding definition of 'Control'.