The landing gear is not meant to be retractable. Retractable landing gear will increase the weight on the rotorcraft, a big no-no for a helciopter desperately trying to shed weight to meet the Air Force's (considerably eased) requirements. The additional weight of associated motors and machinery marginally 'outweighs' (quite literally) the weight of fixed, tricycle-type landing gear. The slow speed of the helicopter, on the other hand, (relative to aircraft) [top speed, estimated at 25kmph above the top-speed of the Dhruv] precluded necessitating its inclusion. The helicopter was a good 300-350 kgs. overweight compared to the Force's original ASQ, and prior to TD-1, its previous testbed designate, was a good 150-175 kgs. over the Air Force's amended (370 vis-à-vis 225 k.g.) weight requirement. Weight issues were supposed to have been mitigated to a limited extent with TD-1, but I don't know how and by how much.
'Course, on the other hand, the existing non-retractable landing gear will increase drag and reduce performance, but I think the Air Force is willing to accept that in exchange for greater reliability and acclivity at the high altitudes of the Himalayas or the helicopter's combat ceiling of 6000 metres.
If by 'closed tail rotor', you mean a fantail assembly tail rotor, then that was not intended either. The LCH is a direct derivative won by a wrap of a slim, tandem-seat fuselage around the existing powerplant, transmission and rotor systems of the the ALH Dhruv, which itself bore a quadruple-blade bearingless crossbeam tail-rotor mounted overtly on the starboard side of the fin. As such, the tail rotor blades were supposed to feature composite, open, bearingless construction, with the main rotor blade tips featuring BERP-style sections for increased cruise speed.
