Magistrate Noorasyikin Sahat handed down the sentence on N.Saravanan, who is in his 30s, after the man pleaded guilty to the charge.
He was ordered to serve the jail sentence from the date of his arrest on Sept 2 last year.
His five friends who were also charged with the same offence pleaded not guilty and were allowed bail of RM1,800 each. The court set Oct 26 for mention.
They are V. K Anith Kumar, S. V. Shashi Kumar, P. Nagulan, M. Parwin and G. Thiagu, who are between 19 and 38 years-old.
The five men were charged with becoming members of “Geng 08”, which is unlawful organisation, in Kuala Lumpur between Aug 23, 2013 and March 28 this year.
The charge, under Section 43 of the Societies Act 1966 provides an imprisonment for up to three years, or maximum fine of RM5,000, or both, upon conviction.
In mitigation, Saravanan, represented by lawyer Jay Moy Wei Jiun, said he had a family to support.
The prosecution was conducted by deputy public prosecutor Muhammad Fadzlan Mohd Noor.