‘R…Rajkumar’ is about a rowdy Romeo falls in love with a village belle, but he has to fight the enemies of love - chachas, chamchaas and cronies - to take home his dulhaniya.

It starts off with Romeo Rajkumar (Shahid Kapoor), an aimless youth who arrives in small town of Dhartipur been ruled by two drug barons named Shivraj Gurjar (Sonu Sood) and his arch enemy Manik Parmar (Ashish Vidyarthi), controlled by a Mafia don named Ajit Taaka (Srihari), who operates in Hong Kong. Rajkumar now works for Shivraj. But his life changes forever when he claps eyes on the beautiful, educated Chanda (Sonakshi Sinha). What he does not know is, that Chanda is an orphan who is being raised by Manik Parmar. After some persistent wooing, Chanda falls for Rajkumar's charms. Just when their love was about to flourish, Shivraj and Parmar compromise and Parmar decides to get Chanda married to Shivraj, against Chanda's wish. Angered Rajkumar beats Shivraj's men and challenges him, saying that he will marry Chanda in front of Shivraj. Furious, Shivraj plans to get Rajkumar killed in an encounter by his pet police officer. But in return, gets a shocking surprise when it is revealed that Rajkumar actually works for Don Ajit Takka and was sent to Dhartipur only to take over the drug cartel to which both Shivraj and Parmar owe allegiance. Rajkumar captures Shivraj's truck full of drugs and drives it to Takka, revealing he himself was a big gangster all along. After giving Shivraj's stolen truck to Takka, he discovers that the truck was empty. In a twist of events, it turns out that Shivraj and Takka had joined hands, and purposely made Rajkumar steal the empty truck. Shivraj and Takka brutally kill Rajkumar and bury him. Shivraj starts his wedding celebrations with Chanda, only to be interrupted by the still alive Rajkumar, who is shown to have been rescued by one of Shivraj's henchmen after he was buried. Shivraj's men back off, because they are now friends with Rajkumar, hence leading to a one on one fight between the two. Finally, Rajkumar injures Shivraj with a power punch to the neck and later kills Don Takka with a ceramic tile.

The film ends with all the men beating Parmar, while a severely injured Rajkumar and Chanda walk away hand in hand happily. The love story lacks emotions and due to this the chemistry doesn't get established making the viewer feel immune to whatever pain the boy is taking for the girl or vice versa.