You can, but will need to order the mounting hardware from Dell to install the drive.  
Hello, I am going to buy dell Inspiron 3511 laptop having i5 512gb SSD Nvidia GeForce mx350 graphics (model no -D560578WIN9SL).So i want to know that can we add 1tb internal hdd hard drive into this laptop.
Can we Add internal hdd into Inspiron 3511