servicing, overhauling, routine & preventative breakdown maintenance and testing of electro-mechanical equipments / accessories in 11 kv / 0.415kv / 0.220kv electrical network system i.e., indoor & outdoor lighting, vrf type central air conditioning system, 11kv compact substation, d.g. set ( only electrical ) , fire fighting system ( only electrical ) etc. from ground floor to 4th floor and basement at nabadiganta bhavanfor a period of one year ( 365 days ) under ndita. ( which may be extended up to 5 ( five ) years on the basis of satisfactory performance and under same rates and terms & conditions ) .