DRT limitation

What is the limit (minimum amount outstanding ) for a bank to file a case in DRT? I have heard that the loans having principle amount outstanding over Rs.10 lacs can be entertained in DRT. Is this true? A friend of mine had taken a personal loan of Rs. 6,50,000/- from a bank in Dec. 2008. He has defaulted in repayment since Dec.2009. Since then nothing happened , but now all of a sudden he has received a summons from DRT in the matter filed by ARC (asset reconstruction company). The matter is not even filed by the bank. Can the ARC directly file the matter in DRT? Is the loan not time barred? Is the law of limitation applicable in this case?