hamzaumarkhan - as you can see from the posts above, you didn't really ask a question. If you want help, please ask clear and concise questions. Estimating could be estimating reinforcing, in which case the answer is either a) hire a structural engineer or b) read a concrete design textbook if you are a junior engineer aspiring to be a structural engineer and come back with specific questions about what you don't understand. It could be about cost estimating, which would be very regionally dependent. You could be asking for rules of thumb. Nobody really knows, because you didn't ask anything.