Representatives from 47 member states elected Rücker to the post in Geneva on Monday.
"This is a unique privilege and a great honour for me and for my home country of Germany," the 63-year-old diplomat said. The new job will see him act as an impartial chairman of the council, rather than representing German interests.
Rücker told reporters that he wanted to speed up the HRC's response to crises, noting that the Council had taken too long to call an emergency meeting in response to the rise of terrorist group Isis.
He also hopes to increase the importance accorded to human rights in the whole UN system, campaigning for more funding.
"Nine years after its founding there are still questions about the functionality and effectiveness of the Council," he told news agency dpa.
"I want to work for a stronger involvement of civil society in the work of the Council and support a culture where there's no place for intimidation and threats against civil society."
But he said that the HRC was already having a serious impact on the world stage less than a decade after its founding.
"The resources that states put into resolution negotiations and Council hearings, as well as the attention that these themes get in the media, are an indicator of how seriously the HRC is taken," he said.
"No state remains silent when it's accused of infringing human rights."
Rücker's third aim will be to crack down on duplicating of work and make sure that the implementation of the HRC's decisions is closely monitored.
But some subjects will make for an uphill battle as they are brought up repeatedly for political reasons, such as repeated attacks on Israel by other Middle Eastern states.
"Israel should be treated like any other state, no better and no worse," he said. "I want to keep all parties from misusing the Council."
Rücker, an economist and former mayor of Sindelfingen in Baden-Württemberg, held high offices at the Foreign Ministry in Berlin before representing Germany at the UN in Geneva.
He has served as German ambassador to Sweden and was also in charge of the UN mission to Kosovo.