Domain name has been delegated, but a website with this name does not open. What should I do?

You may use website check service which will advise you on probable solution.

Besides, it is recommended to make sure that A record for your domain is available on DNS servers which your domain name is delegated with.

A check on which DNS servers test.ru is delegated with can also be done in Whois. 

Querying the DNS server can be done with nslookup command.

If the corresponding A record is available, probably the changes had been made too recently and there was not enough time for information to reach DNS server used by your local PC. In this case it makes sense to wait till information is spread automatically (usually it takes not more than 24 hours) .