Using two different frequencies RAM together

[Nischhal]

My notebook has 2GB DDR3 PC3 RAM, I want to upgade it to 6GB. So, I want to add 4GB DDR3 PCL3 RAM. Willl it damage my PC or create any sort of problem if I used those two RAMs of different speed and voltage together?

[Huffer]

Well your laptop takes DDR3-1333 SO-DIMM memory. You would be best served to get that. It is 1.5 volt memory. Having said that DDR3L is 1.35 memory which will also run at 1.5 volts if it must, which it must on your system. DDR3L-1333 may exist but its impossible to find and likely you can find DDR3L-1600 very easily and for less money. Likely, probably DDR3L-1600 will downclock to 1333 and run at 1.5 volts for you but you are asking a lot of adjustments and it might not work. It will not harm the laptop. Worst case your laptop will not boot up. It may work but will not be dual channel as that takes 2 modules the same size and speed. 

Post back with any more questions and please accept as solution if this is the info you needed.