Development charges in DC Colony Phase III

Aoa

1.5 years ago I bought 1 kanal plot DC colony phase III.

November 2011, transferred through DC colony office to my name. When I have seen the file it was showing development charges out standing Rs 6,00,000 (6 lac) that time I understand may be this charges for every body but when I have seen others friend documents. The balance was zero. What can be reason for balance due in? May be you have any idea about this. Advise me with thanks.