There are some restrictions of course. When you ask "...can support up to 3 TB RAM?", you probably mean RAM like DDR? Here the T4240 is not a bottleneck, problem is rather with the RAM itself.
The T4240 supports DDR3/L memory and contains three DDR controllers with four memory banks (Chip Selects) each. In turn the the maximum volume of DDR3L devices is 8Gb. Assuming the user uses x4 devices and 64-bit bus width, the number of devices per one Chip Select is 16 pieces, that is 16 x 8Gb = 16GBytes. For Chip Selects provide 4 x 16GBytes = 64GBytes. So three DDR controllers can support maximum 3 x 64GByes = 192Gbytes, that is maximum supported DDR size.
The T2080 supports only x8 and x16 device organization, so in maximum it supports 8 x 8Gb =8GBytes per one CS and 4 x 8Gbytes = 32Gbytes per the DDR controller, i.e. per the T2080.
These numbers can be found in the Ref Manuals, see sections 'Supported DDR SDRAM Organizations' .