Hello,
it is not possible to install a Kraken X63 in the lid of a non-modified H510 Elite case, as there is only one 140 fan slot. However, the NZXT Kraken X63 is an AIO with a radiator size of 280 mm (2x140 fans). This means that the AIO can only be installed in the front of the case. As an alternative for the 140 fan space in the lid of the case, I recommend an Alphacool Eisbaer 140. If you want to stay with NZXT (which is a very good choice, by the way), you can also install a 120 AIO NZXT Kraken M22 at the rear of the case.

With kind regards
Night Grey

You must position yourself in front.