I would like to convert my name to korean, but I am having trouble with "泽" which can be 석 or 택. I would assume the name would be 하석민 or 하택민 after conversion. Does it matter which one I use?
When we do not consider a pronunciation-based name as another option, I believe that 하택민 is the safest choice because of these three reasons:
Koreans do not use Simplified Chinese characters, such as 泽, so you should use Traditional Chinese characters or Hanja instead. 澤 used for a personal name has to be pronounced as 택 in South Korea. By law, there are no options to its sound.
택민 does not sound strange at all. Some Koreans have it as their first name.
If you use 석민, public servants or other workers could make mistakes about your name when they use the "Korean character to Hanja" converter. For 석, the Hanja lists of Windows 10 and the word processor 한글 have neither 澤 nor 泽. It matters if you do not want to waste time on this.
I have no idea why you wish to use a Korean name, but if you are going to live in South Korea, you should conform to Korean customs and obey the law.