TAN not available for TDS on sale of House Property

I sold house property to joint buyers.  They have dedcuted 1 % TDS and the same is reflected in AIS properly.  While filling Schedule TDS2 in the ITR Form (ITR 2), the TAN of deductor is required.  But as these buyers are individuals no TAN is avaialble.  The AIS shows acknowledgement number, PAN number of deductor and TDS certificate number.  

How to fill in the TAN column in Schedule TDS 2 in the above scenario?