What kind of stuff are you rendering? For large environments, you probably want more VRAM - 6 GB vs 4 GB VRAM will make a huge difference for environments or volumetrics. If you’re doing hard surface stuff or characters, it’s more about the CPU, you won’t really notice a difference, so you can go with the cheaper one
I’ll be dealing with volumetrics and environments for still renders, halfway between realism and art, with soft lighting and such, but my animations will be on eevee. Most of the stuff I’ll do will be eevee but with occasional cycles.
However, you should also consider other options than the 3060. When it comes to NVIDIA graphic cards, the model number represents two thing: the generation, and the series. For example, 3060 means it is the third generation of XX60 model.
And the thing is, older GPUs are way cheaper for its comparative performance. So if you can find a laptop with RTX 2060 in it, it most likely will be cheaper. The 2060 also already has 6 GB of VRAM, so it’ll be enough for your purpose.
However, since the 3060 is basically the third version of XX60 model, it actually performs poorer than 2070, 2070s, 2080, 2080s, and 2080Ti, even though it’s the third generation.
So try searching for laptops with RTX 2070, 2070s, 2080, 2080s, and 2080Ti as well, and note the price. Then you can pick one which fits your budget perfectly.