Section 54

You cannot avail the exemption u/s 54F for all the properties to be acquired....Provisio to section 54F clearly prohibits such a situation

you can get deduction for one house by purchasing one house only...

There is no clarity in law whether you have to invest all cap gains in 1 house or more than 1 house

 

And in such a case, different people are taking out different interpretations..

https://www.itatonline.org/forum/index.php?topic=428.15

as per your question it seems that there are two properties.. one on mother's name and other on joint name.. thus you can sell properties individually and buy another property on that name.. 54F talks about buying one house if you do not have a house or second house considering you do not have more than one house. thus sell property in a way that you do not have more than one house at any time. sec 54 talks about sell a house and buy a house.. thus you can make as many transactions you want by selling a house and buying a house. regarding the question of buying multiple properties after selling one property at a huge price, then there are judgments supporting also and against it also.. generally the revenue is on a positive note in such cases.. eg: a person shifting from mumbai to ahmedabad selling his mumbai flat for about 6cr and buying a flat in ahmedabad for 1.5cr and another land for making house for 1cr will normally be accepted !