That is probably worth what you pay for it. I'd be happy to let an Indian lawyer review documents under Indian law but for a situation in the US or in Europe I'd use a local lawyer specializing in the problem ___domain (in this case labour law).

'Generic legal language' is not your problem, specific legal language applicable to this specific case is the problem and if $20 is the differentiating factor then you might as well quit the job or sign the contract anyway.