Design, programming, installation, supply, testing and commissioning of distributed type ( 01 central cabin and 03 end cabin ) electronic interlocking (ei) system conforming to rdso specification no. rdso/spn/203/2011 or latest (with latest amendment if any) for gorakhpur jn. station as per sip along with indoor & outdoor work including part supply of materials at gorakhpur jn. and design, programming, installation, supply, testing and commissioning of centralised electronic interlocking (ei) system at nakaha jungle station conforming to rdso specification rdso/spn/192/2019 ver.2 or latest (with latest amendment) along with indoor & outdoor works in connection with provision of double line between gorakhpur - nakaha jungle section in lucknow division of n.e. railway.station in lucknow division of n.e.railway.