WHOIS Details:

WhoisDog failed to connect to WHOIS server: whois.dotmobiregistry.net

Root Zone Database:
https://www.iana.org/domains/root/db/mobi.html

Try these WHOIS services:
http://whois.dotmobiregistry.net
http://tian.hu/186.mobi
http://whois.gd/186.mobi
http://who.cx/186.mobi
http://whois.domaintools.com/186.mobi
https://whois.gandi.net/en/results?search=186.mobi
https://www.godaddy.com/whois/results.aspx?checkAvail=1&domain=186.mobi&prog_id=GoDaddy
https://www.namecheap.com/domains/whois/results.aspx?domain=186.mobi
https://who.is/whois/186.mobi/