Currently you can upgrade your SAMSUNG Galaxy TAB Android to Lollipop 5.x. For this you need to download Lollipop 5.x firmware in accordance with the model and type of your Samsung Galaxy. To get the type and model, then you can see the rear casing tab, or it can be from the settings menu.
First, please download the firmware in accordance with your tab, you can download

Second, please download the tools used are Odin in  at the end of the document.

Then follow the steps contained in the
I've tried with a Samsung Galaxy Tab 4 8.0, SN-T331 models and run well. Good luck.