JUDGMENT :

R.D. Dhanuka, J.

1. By this petition filed under Article 226 of the Constitution of India, the petitioners have prayed for a declaration that Regulation 33(5) of the DEVELOPMENT CONTROL REGULATION s (hereinafter referred to as ‘the said D.C. Regulations’) permits utilization of area which is free of FSI area including staircase, fire escape staircase, car park area, staircase room, lift machine room, lift rooms, lobby, elevated water tanks in buildings for rehabilitation component on the land described in the petition without payment of premium. The petitioners have also impugned an order dated 6th January, 2018 and seeks refund of Rs.27 crores along with interest incurred thereon and for other reliefs. Some of the relevant facts for the purpose of deciding this writ petition are as under:-

2. The petitioner no.1 is an Apex Society incorporated under the provisions of the Maharashtra Co-operative Societies Act, 1960 and is the lessees of the respondent no.2 i.e. The Maharashtra Housing and Area Development Authority (MHADA) with respect to all that piece and parcel of the land situate and lying at Survey Nos. 55 and 56, CTS No. 837 to 840 of Village Poisar, Taluka Borivali, admeasuring 2,13,867.50 square meters or thereabouts situate at Samta Nagar, Kandivali (East), Mumbai – 400 101 (hereinafter referred to as ‘the said land’). The petitioner no.1 comprises of 65 societies and are constructing buildings including rehab buildings for about 1955 individuals/members of the societies who belongs to Economical Weaker Sections and Low Income Group.

3. The petitioner no.2 has acquired the development rights with respect to the said land from the petitioner no.1 and other 65 individual societies. The respondent no. 2 is the owner of the said land. There were about 165 structures/buildings on the said land which are now being re-developed by the petitioner no.2.

4. Sometime in the year 1961-62, the respondent no.2 had developed 160 buildings having 2714 tenaments for different income groups such as (i) High Income Group – 12 buildings – 240 tenaments, (ii) Middle Income Group – 35 buildings – 700 tenaments, (iii) Low Income Group (LIG-Big) – 45 buildings – 672 tenaments, (iv) Low Income Group (LIG Small) – 31 buildings – 816 tenaments and (v) Economical Weaker Section – 37 buildings – 296 tenaments.

5. On 3rd October, 2007, 29th February, 2008, 20th June,2014, 1st July, 2014 and 31st March, 2016, the respondent no.2 issued Letter of Offer to the petitioner no.1 for certain buildings comprising of about 1784 tenaments out of 2714 tenaments for integrated development in the layout.

6. On 25th October, 2010, the petitioners no.2 submitted a proposal for building no.1. On 26th November, 2010, the respondent no.1 issued IOD in respect of the said building no.1. On 25th July, 2011, the respondent no.1 issued commencement certificate. On 15th January, 2016, the respondent no.1 approved the plans for building comprising of 7 wings for various floors. On 16th April, 2016, the petitioner no.1 applied to the Deputy Chief Engineer, Building Proposal Department for relaxation/concession by not charging any premium in accordance with Regulation 33(10), Clause (6) of Regulation 33(5) read with Sub-Regulations 6.21 and 6.22 of Appendix IV of the D.C. Regulations. The petitioner no.1 submitted amended plans for building no.1 (rehab building).

7. By letter dated 22nd April, 2016, the Deputy Chief