As per the official website of Ranchi University it is stated that the online admission of UG regular courses have started through chancellors portal.I recommend you to keep visiting this official site-

https://www.ranchiuniversity.ac.in/index.php?option=com_content&view=article&id=32&Itemid=449

and the chancellors portal- https://jharkhanduniversities.nic.in/home for important updates and notices.