Identifying Fake Form 16 Documents
Firstly, you can't identify a fake Form 16 against the original easily, but I would suggest that you read the clauses carefully and compare them to the original one. Look out for the official seal if it's already been executed.
Secondly, collect the company-related original details of deductions and ask for the verification slip from the company. In case of huge fraud or misrepresentation, you may seek assistance from the Income Tax Department by providing the employee tax code details to them and lodge a complaint.
For more details, call the toll-free number [Phone Number Removed For Privacy Reasons] and inquire about the steps taken to prevent fraud and how to distinguish between a fake and an original. (It's a Toll-Free Government Official Number, Ayakar Seva Kendras).
In fact, I did call them up. The first call was disconnected. The second time, I spoke to a person who could not grasp the question and said he would transfer the call to his senior. After waiting for a few minutes, he informed me that the senior was busy and there is only one Form 16. I thought there was no point in continuing the conversation, so I said I would call them later. Funny and weird experiences! Relying on official sources in many matters is often just a waste of time.
Cross-verifying with the company that issued the acknowledgments is the best way to differentiate between fake and original documents.