In this Act, unless the context otherwise requires,--
         (a) "Coal India" means the Coal India Limited, a Government company incorporated under the Companies Act, 1956 (1 of 1956) having its registered office at Calcutta and includes its predecessor Government company, namely, the Coal Mines Authority Limited;
         (b) "subsidiary company" means the following subsidiary companies of Coal India, namely:--
             (i) the Central Coal Fields Limited, Ranchi and includes its predecessor Government company, namely, the National Coal Development Corporation Limited, Ranchi;
             (ii) the Bharat Coking Coal Limited, Dhanbad;
             (iii) the Western Coal Fields Limited, Nagpur;
             (iv) the Eastern Coal Fields Limited, Sanctoria;
             (v) the Central Mine Planning and Design Institute Limited, Ranchi;
             (vi) the South-Eastern Coal Fields Limited, Bilaspur;
             (vii) the Northern Coal Fields Limited, Singrauli;
             (viii) the Mahanadi Coal Fields Limited, Sambalpur;
and includes such other subsidiary company of Coal India as may be incorporated under the Companies Act, 1956 (1 of 1956) from time to time;
         (c) words and expressions used herein and not defined but defined in the Coking Coal Mines (Nationalisation) Act, 1972 (36 of 1972) or the Coal Mines (Nationalisation) Act, 1973 (26 of 1973), shall have the meanings, respectively, assigned to them in those Acts.