Rights of first owner in a property

Hi, My husband and his mother owns a flat in a cooperative society in Mumbai, he wasnt earning much at that time so did not contributed much to the capital (2014) however the deed simply ask the developers (i.e. builders of the society) to transfer this property in name of purchasers i.e. 1) My mother in law's name , 2) My husbands name in that order resp, however no division like 50 -50% or any other ratio is mentioned, nor is it specified categorically that MIL is the first owner (apart from serial no 1 &2) Now my questions are ;- 1) is mother in-law the first owner here ? If yes are there some special rights given to first owner 2) Since the deed doesn't specify ratio of capital paid or the ratio of property each has should we assume its 50-50? 3) The share certificate which is yet to be formed or come, will it automatically state both my husband and mother -in law as a 50-50 partner or do we have to fill it like that/ ( please elaborate on share certi) if she makes nominee to ?