The written name Hala can be pronounced in 3 different ways according to which the meaning varies. If pronounced Haala (the emphasis is on the first syllable) it means halo around the moon,if pronounced Hala (just as it's written) it means welcome. The third meaning comes from pronouncing the H differently - it's a letter that exists almost exclusively in Arabic. The meaning then becomes: beauty. In Arabic, of course, each name is written differently. Three different pronunciations, three different names.
This name reminds me of "Hala Madrid!", the sentence Real Madrid's fans use. In Croatian it also means "a hall", so, I don't think I would use it. It is a nice name nonetheless, and other people are free to use it.