In the absence of any written agreement with regard to rate of interest - the plaintiff is entitled to interest only at the rate of 6 per cent. as per section 80 of the Act

in the absence of any written agreement with regard to rate of interest or acceptable evidence and when the instrument is silent as to the rate of interest, the plaintiff is entitled to interest only at the rate of 6 per cent. as per section 80 of the Act. The same view has been expressed by Swamikkannu J. in a decision in 

Syndicate Bank v. N. C. Kalyani, 

AIR 1985 Mad 254.