A river of words flowed between us.
The Sixers are a section of the Innovative Online Industries who concentrate on finding Haliday's egg. The IOI (pronounced “eye-oh-eye”) was initially a global communications network and internet service provider, but now also provides access to the OASIS and sells goods/services within it. The Sixers were created by the IOI to search for Halliday’s Easter egg and seize control of Halliday’s fortune.
They are called Sixers because each employee has an employee number and avatar name that is six digits long and starts with the number six. The Sixers are contract-bound employees who are provided with paychecks, food, lodging, retirement, etc. All Sixers, regardless of gender, take on an identical male avatar within the OASIS.
They are hated by gunters because they have seemingly endless funding to cheat to get the egg. The sixers main goal is to find the egg for IOI which is bad because, if they win, they will put a monthly fee on users of the OASIS and introduce advertising.