The following information was obtained from The Joshua Project. I am not sure how reliable it is. Still waiting for the 2012 Tamil Nadu Caste Census report to be out.
The total population of Tamil Nadu in 2011 was 72,138,958.
The combined Mukkulathor population is 4,971,000.
That is around 6.89% of Tamil Nadu population.
Founder & Admin of Facebook Malaysian Mukkulathors