Section 211. Exemption from increase in local taxation

1.  A  local
  legislative body is  hereby  authorized,  by  adopting  or  enacting  an
  ordinance  or local law, to exempt all or part of the real property held
  by redevelopment corporations during a maximum exemption  period,  which
  shall  not  exceed  ten years, which represents an increase in any local
  tax over the maximum local tax. After the adoption or enactment of  such
  an  ordinance  or  local  law, every parcel of real property held by any
  redevelopment corporation in the city shall be exempt during the maximum
  exemption period, from that portion of each and every local tax  to  the
  extent  that  such exemption has been granted by such ordinance or local
  law. If, during the last year of  the  maximum  exemption  period,  such
  exemption  is  in  existence  on  the day such local tax, or installment
  thereof, becomes a lien on such parcel of real property, such  exemption
  shall  extend  for the full tax year for such local tax and shall not be
  apportioned because of the expiration of the  maximum  exemption  period
  during such tax year.
    2.  For  the purpose of fixing the date of commencement of the maximum
  exemption  period  for  a  group  of  parcels  of  real  property  in  a
  development  area, a city is hereby authorized, with the approval of its
  local legislative body, except that if there is a board of  estimate  in
  the  city,  then with the approval of the board of estimate, to contract
  with a redevelopment corporation to place in  one  or  more  groups  the
  various  parcels  of  real property therein. Such a contract may provide
  that all of the parcels in each group may be deemed to have had a common
  stated date of acquisition by the redevelopment corporation,  regardless
  of the actual date of acquisition of each parcel contained therein. Such
  agreed  date  of  acquisition  shall  thereupon  serve  as  a  basis for
  computing the maximum exemption period for each parcel of real  property
  in  the  group.  Such agreed date of acquisition shall not be later than
  the date of the actual acquisition  of  one  or  more  parcels  of  real
  property in the group. After the making of any such contract, all of the
  parcels  of  real  property in any such group shall be treated as a unit
  for the purposes of the assessment and collection of each local tax, and
  the maximum exemption period so computed shall be binding  with  respect
  to each local tax.