It's been rumoured before, but a webshop has now shown a GeForce RTX 3060 Ti with GDDR6X memory (not GDDR6). 

The GeForce RTX 3060 Ti has debuted in UK web store Scan. Thhe UK, this retailer sells Nvidia's own Founders Editions. Users could place an RTX 3060 Ti Founders Edition in their buying basket, revealing that the video card includes GDDR6X memory. This video card has 4864 CUDA cores and 8GB GDDR6 RAM when it was released. Other parameters appear to be substantially unchanged. The reference to GDDR6X RAM appears to have been removed. As a result, it is also possible that this is a store error. 

This new variety, according to current speculations, could be released "around the end of October." 

A Faster NVIDIA GeForce RTX 3060 Ti (with GDDR6X memory) inbound?