If you are downloading this App from your phone please check into download location there must be a file by name eMedicoz.apk.
Click on eMedicoz.apk it may ask you to enable Install from Unknown source you need to enable that for eMedicoz.
If you are downloading the app on a laptop, you need to copy and paste eMedicoz.apk into your phone after pasting click on eMedicoz.apk and phone may ask to enable Install from Unknown source. You need to enable that for Emedicoz App only.