Meaning:
This term refers to the widely complained-about practice of some tech firms in China that require their employees to work regularly overtime, i.e., working 9 a.m. to 9 p.m., six days a week. In other cases, even when their company does not require the employees to work overtime, people stay voluntarily in the office driven by peer pressure.
Example:
A: 听说你们公司准备996了？
Tīngshuō nǐmen gōngsī zhǔnbèi jiǔjiǔliù le？
I’ve heard that your company is planning to require people to work 9 a.m. to 9 p.m., six days a week. Is it true?
B: 没听说啊。有些研发部门的人很拼是真的，但公司没有硬性规定。
Méi tīngshuō a。Yǒuxiē yánfā bùmén de rén hěn pīn shì zhēnde，dàn gōngsī méiyǒu yìngxìng guīdìng。
I’ve heard nothing like that. Some guys in the R&D work really hard, but the company doesn’t make it compulsory.