Gandhi on Thursday pleaded 'not guilty' in the court in the defamation case after he accused the RSS of being responsible for the murder of journalist Gauri Lankesh.
"Think you know what the RSS is all about, think again. The Rashtriya Swayamsevak Sangh has consistently participated in anti-India activities, including pledging loyalty to the British, instigating violence & assassinating Mahatma Gandhi," the Congress said on Twitter, using hashtag "RSSVsIndia".
"From the freedom struggle to the symbols of Indianness, the RSS has always opposed them. When freedom fighters were fighting the British, the RSS as an institution was bowing before the British. Opposing the "idea of India" has been the policy of the RSS," the party also tweeted.
The one-minute video titled "RSS for Dummies" alleged that RSS founder 'KB Hedgewar ordered the Sangh not to participate in Satyagraha'. "Sangh leaders encouraged members to join the British civic guard... RSS' non-participation in India's Independence was complimented by their British masters... The Sangh opposed our national flag! Anti-national, much? Nathuram Godse shot and killed Gandhi," the party claimed.
It also alleged that "the RSS opposed liberalisation... In short and in shorts, the RSS is anti-development and fought against freedom when we fought for it".
The video also alleges that the RSS considers the 'Manusmruti' greater than the Constitution.
The video comes a day after Gandhi formally resigned as Congress president while taking full moral responsibility for the party's Lok Sabha poll debacle.
In his four-page farewell letter, Gandhi also said the RSS succeeded in its mission to capture India's institutions.
"The stated objectives of the RSS, the capture of our country's institutional structure, is now complete. Our democracy has been fundamentally weakened. There is a real danger that from now on, elections will go from being a determinant of India's future to a mere ritual," he wrote.
"This capture of power will result in unimaginable levels of violence and pain for India. Farmers, unemployed youngsters, women, tribals, Dalits and minorities are going to suffer the most. The impact on our economy and nation's reputation will be devastating. The Prime Minister's win does not negate the breadth of corruption allegations against him; no amount of money and propaganda can ever hide the light of the truth.
"The Indian nation must unite to reclaim and resuscitate our institutions. The instrument of this resuscitation will be the Congress party," Gandhi said in his letter.