@User1218 wrote:
If there was "right of survivorship" then should all of the sale proceeds be reported on my grandmother's return or would it still be split between both her and the estate?
No, if the account were held as JTWROS (rights of survivorship) then your grandmother succeeded to your uncle's share by operation of law (bypassing his estate). As a result, the entire proceeds would be reported on your grandmother's return.
You still need to seek professional guidance and there is the matter of stepped-up basis upon the death of your uncle.
