If these are Windows-based mobile workstations (a big mistake if security is a concern, but I desist to understand corporation policies related to computer security) there is a chance they will come with TPM 1.2 enabled by default.  You can change the TPM mode between 1.2 and 2.0 on most workstations manufactured in the last four years by following the steps documented here:

http://en.community.dell.com/techcenter/enterprise-client/w/wiki/11850.how-to-change-tpm-modes-1-2-2-0

Hi jwc121401,

I'm afraid it's not possible with the systems that you mention. Here's the list of those that do support mode change:

 http://en.community.dell.com/techcenter/enterprise-client/w/wiki/12265.dell-tpm-platform-support

I see in the bios that TMP 1.2 has subset 2 and 3 or is the ppi version that needs to be 2.0?

If other computers with the same TMP 1.2 version can select or upgrade which type or version why can't The M series? They have the same TPM hardware do they not? So we can deduce that its not a hardware issue. So the only other issues it could be is the firmware or BIOS unless it's a licensing issue. What is it that limits the firmware in one computer as compared to another with the same hardware? A BIOS that doesn't support the settings? If so can't we modify the BIOS or find a BIOS that does? 

I have 2 Precision dell M4800, purchase cost 8000 $ and I was very disappointed by the dell brand that has not found a solution to the problem .... We are not talking about Chinese cell phones costing $ 50 ... this commercial policy it is unacceptable

These are 8-9 year old systems that have outlived their design lives by a factor of up to three. 

It is completely unreasonable to expect TPM upgrades on systems that went end of life more than five years ago - no manufacturer supports  hardware indefinitely.

Although it is not possible to upgrade the OS to Win11 with TPM1.0 on M4600 and later, a clean install is possible.

@user_73a6d9​ 

Successful installations of Windows 11 have been seen on the M4600, M4700, M4800, M6600, M6700, and M6800.
Installing on the M6600 and M4600 requires a little ingenuity.
All can be installed by booting from USB.