An usual top-level domain (TLD) has a minimum length of 2 characters. Is this rule applies to Internationalized TLDs too (like .中国 .مصر .भारत)?
I'm writing a Regex to validate email.
Yes, it applies, two letters is the minimum for IDNs as well. It may however be relaxed in the next year or two, single-character IDN TLDs have been proposed for Chinese. I don't think any decision has been made.