I have a 6x4 meter area. Adobe Illustrator doesn't support 6m Artboards. How can i design a 6x4 meter area in Adobe Illustrator?
Because Illustrator is vector, so you can scale your graphics indefinitely. For this reason you don't need to make your artwork 1:1. Just make your graphic 2:1 or 10:1 and then label your file clearly that it is 2:1. Don't forget to inform your client / printer of the ratio in an email too (always keep that clear paper trail just in case).
The only consideration you need to make is if you add any raster images, in that case, scale them according to your scale (so if it's 2:1, make the DPI twice as high, remember that usually you don't need as high DPI when if the end product is this big). You mentioned in the comments that it's for an exhibition. Because of the size of the wall, I would suggest you have your 1:1 resolution at around 72-100 PDI if people will be viewing from 3-6ft away, however if people will get quite close (closer than 3ft), maybe use 150-200 dpi. However, always ask your printer! They might advise you to use a certain DPI and you should always follow their advice.