Bluestacks requires a minimum of 2 GB RAM for a reason. It you don't meet the requirements, Bluestacks will work very slow and the general performance will be something you don't want to use, therefore you actually need a minimum of 2GB or even more (8-16 GB recommended for High Performance).
There are third party applications on Internet with this limit removed, but I wouldn't recommend them at all since malware can be bundled as well.