"Maybe there is something missing in my penance," Mr Khera tweeted in Hindi.
The Congress leadership has come under criticism after it left out prominent leaders, including party spokesperson Pawan Khera, while selecting candidates for Rajya Sabha.
Mr Khera, known for his feisty defence of the party line in TV debates and media interactions, expressed his disappointment with a Hindi tweet after the Congress released its list of 10 candidates for the upper house.
"Maybe there is something missing in my penance," Mr Khera tweeted in Hindi.
Mr Khera later congratulated his party colleagues who were chosen by the high command.
He also attempted to play down his disappointment by saying that it is the Congress which gave him an identity.
Sharing a clip of an earlier interaction with AajTak, he said, "'The Congress gave me an identity'. I still stand by this statement of mine," he tweeted.
Responding to a Twitter user who suggested him to "live for the country and not for a family", Mr Khera said, "The family I stand with lives for the country and dies for it. Those with Sangh Parivar can't understand this feeling."
The Congress has fielded Rajeev Shukla and Ranjeet Ranjan from Chhattisgarh, Ajay Maken from Haryana, Jairam Ramesh from Karnataka, Vivek Tankha from Madhya Pradesh, Imran Pratapgarhi from Maharashtra, Randeep Singh Surjewala, Mukul Wasnik and Pramod Tiwari from Rajasthan and former Home Minister P Chidambaram from Tamil Nadu.
The party has come under criticism for its Rajasthan candidates, none of whom hail from the state.
Sanyam Lodha, Congress MLA from Sirohi in Rajasthan, said the party will have to explain why no one was nominated from the state. "The Congress party should tell what is the reason for not making any Congress leader/worker from Rajasthan, a candidate in the Rajya Sabha elections?" he tweeted.
The party was also criticised on social media for not accommodating veteran leaders Ghulam Nabi Azad and Anand Sharma.
The party's move to select poet-turned-politician Imran Pratapgarhi also came under criticism. Party leader and popular actor Nagma shared Mr Khera's tweet and wrote, ""Our 18 years of penance also fell short in front of Imran Bhai."
The actor also said Congress president Sonia Gandhi had "personally committed to accommodating" her in Rajya Sabha when she joined the Congress in 2003. Citing Mr Pratapgarhi's selection, she asked if she is "less deserving".
The BJP's Rajasthan unit chief Satish Poonia took a swipe at the Congress over its choice of candidates. "Congress's Chintan Shivir took place in Rajasthan. Now look at another achievement of this thinking. Observe the quota of local candidates....without 'local' who will be 'vocal'..?," he tweeted.
Elections to 57 Rajya Sabha seats spread across 15 states will take place on June 10.