For MATLAB R2011b and all other older versions, you can find the path to MCR installer file by running the following command on MATLAB command prompt.
You can share the mcrinstaller.exe file present in the path to your customers.
You can also package the MATLAB Compiler Runtime (MCR) along with the application you want to deploy. In this method, when the client runs the deployed application, the installation of MCR is triggered in the beginning followed by deployment of the application.
Note: You will not be able to deploy applications if there is any mismatch between version and bitness of MATLAB (used for compilation) and MATLAB Compiler Runtime (MCR). It is important that you chose the correct MATLAB Compiler Runtime (MCR) with same version and bitness as MATLAB (used for compilation).
For versions R2012a and onwards, customers can download the MATLAB Compiler Runtime (MCR) file here on the MathWorks website.