Sir/ Ma'am,
AS per your stated facts, if there is no proof whatsoever of jointly paying the amount of consideration while buying the property, then there is no way that their contention would stand as per law.
If the property is outrightly bought by your mother, with her own money and can prove the same, there is no ground of the other parties claim at all. Moreover, if you have filed an eviction application, then no question regarding the title shall be raised in that.
if you have filed a Civil suit for declaration and permanent and temporary injunction, then she can raise her arguments, although it won't stand good in law if not backed by any proof.
Abhishek Sharma, Advocate
Punjab and Haryana High Court