@Riz J RE price is 10, means you will get number of share you purchase to apply shares. When you receive it in your account, you have to apply for the shares at what price the company is offering. Take care about dates.
Total : RE Price + share price of offer in right issue.
So 10 + offer right price. If it is quite below 29, it will give you profit, otherwise you have to decide.
Select good company.
Hope this will clear your doubt.