INHERITANCE

Assalamualaikum,
After the death of our beloved father, please clarify the inheritance issue w.r.t. following details-
1. We are five brothers (S1, S2, S3, S4, S5), S1 is eldest & S5 is youngest with no sisters
2. Our mother is Alhamdulillaah alive
Our father had following property
1. Plot-A
2. Plot-B
3. Plot-C (divided as C1 & C2)
4. Plot-D (Registered with mother’s name & verbally gifted to S5 & all know about this)
5. Plot-E
6. Building-A (plot in two parts A1 & A2; A1 plot amount was given by S1 & also registered with S1, father had said Building-A1 belongs to S1, Building- A2 was gifted to S4 and was also confirmed in writing))
7. Building-C (registered with S3 & father has said belongs to S3, although some shops father used to say that it should be given to other brothers also)
We were a joint family. For sometime my father had a property business in which S2 & S3 assisted him. S2 assisted father for 3 years, then father helped S2 & S3 to setup a hardware business which resulted in loss and therefore closed. Father sent S2 to Saudi Arabia. S2 claims that during the period he assisted father he got no compensation. S2 also claims that after going to Saudi Arabia he used to send all the salary to mother’s account. Father used to say that whatever S2 has given, he gave to his mother & its Hiba & former has no connection with it. S2 was also got married and money was spent in that also by parents.
Plot-E was purchased by father but got it registered in the name of S2. S2 claims that father used to say that this plot belongs to S2. When S2 became financially weaker in the later years, he argued to father that he should be given Plot-E, as a compensation to what he served. Father angrily gave that to S2.
Later on, S2 claims that Plot-C was purchased with his amount sent from Saudi Arabia. Father had said that Plot-C was purchased with father’s amount. Plot-C got registered as C1 & C2, C1 on S2’s name & C2 on mother’s name. Mother claims that C2 was gifted by father to her. Other brothers made no claim on C1 as it was registered with S2.
Now, whatever was not gifted (Plot-E & Plot-B) was divided as per inheritance law.
S2 claims that his share is less therefore his dispute for Plot-C should be given in his favour.
Also note that S1 & S5 also used to give good amount to the mother for which they don’t claim anything from her.
Kindly advise regarding the stance of S2 & if the division is acceptable as per shariah. All other brothers have no other claims.