( 1 ) THE petitioners numbering six by this petition filed under Article 226 of the Constitution seek a mandamus directing respondents I and 2 to stop and prohibit the third respondent from commencing/carrying on any commercial activity in the property beang No. D-1097, New Friends Colony, New Delhi, and further restraining the third respondent from carrying on any unauthorised construction in the property. Mandamus is also sought directing respondents I and 2 to proceed against the third respondent under the provisions of the Delhi Municipal Corporation Act, 1957, and the Delhi Development Act, 1957. The First respondent, as seen above, is the Municipal Corporation of Delhi (MCD) and was constituted under the Delhi Municipal Corporation Act, 1957 and is charged with various functions as mentioned in that Act relating to the municipal government in Delhi; the second respondent is the Delhi Development Authority (DDA) and was constituted under the Delhi Development Act, 1957, which Act provides for development of Delhi according to plan and further matters connected therewith; and third respondent is Vinod Sachdeva, occupier of property bearing No. D-1097, New Frien