It should be able to support 16GB of DDR3 1333Mhz Ram as you have 2 slots. Micron aka Crucial and Kingston are pretty good brands. There are many "Brands" but the actual main chip producers are few like Hynix, Samsung, Micron with most of the producers using chips from these guys.

Max RAM on that model is 2X4 = 8 G.

http://www.crucial.com/usa/en/compatible-upgrade-for/Dell/inspiron-15-%28n5050%29

It's not an OS limit - it's a limit of the mainboards in these N-series systems.  They will not take more than 8G of RAM total.

Its not "officially" supported but a few people have upgraded anyway as I said the memory controller is in the CPU not the chipset/motherboard. I have seen artificial limits like this before in some other models. Its up to the OP though if he wants to try or not. Crucial will only list officially supported specs on their site even if you can add more.

 The guy in the following thread actually upgraded the RAM/CPU.

https://hardforum.com/threads/upgrading-dell-inspiron-n5050-cpu.1809113/

That may well be, but it's not guaranteed - it's experimental.  Users should know that before attempting the upgrade.

However, there CAN BE built-in limits to the mainboard support that restrict those of the memory controller.  The system was not designed to run with more than 8G of RAM, period.  It may in some cases - but then again, given the budget nature of these systems, it's really a moot point - anything needing more RAM is better run on a more capable system.

You can turbocharge the engine in a Hyundai Accent, but it remains an economy car.