Spacing between railing bars in stair case as per IS code provisions

Staircase requirements
As per factories Act, 1948, staircase requirements are as follows:
(y)Where stairways discharge through corridors and passageways, the height of the corridors and pasageways shall not be less than 2.4 metres.
(aa)A staircase shall not be arranged round a lift shaft unless the latter is totally enclosed by a material having a fire-resistance rating not lower than that of the type of construction of the former.
(bb)Hollow combustible construction shall not be permitted.
(cc)The minimum width of an internal staircase shall be 100 cm.
(dd)The minimum width of treads without nosing shall be 25 cm. for an internal staircase. The treads shall be constructed and maintained in a manner to prevent slipping.
(ee)The maximum height of a riser shall be 19 cm. and the number of risers shall be limited to 12 per flight.
(ff)Hand rails shall be provided with a minimum height of 100 cm. and shall be firmly supported.
(gg)The use of spiral staircase shall be limited to low occupant load and tea building of height of 9 metres, unless they are connected to platforms such as balconies and terraces to allow escapees to pause. A spiral staircase shall be not less than 300 cm. in diamter and have adequate head room.

As per National Building Code explanation:
Handrails shall be provided at a height of 1000mm to be measured from the base of the middle of the treads to the top of the handrails. Balusters / Railing shall be provided in such a way that the width of staircase does not reduce. The maximum gap between balusters shall be 150mm.

As per IS code 1644-
-Clause no. 2.10.9 : Hand rails should be provided at a minimum height of 100 cm and not exceeding 120 cm to be measured from the base of the middle of the treads to the top of the hand rails. Further, the gap between the two verticals should not exceed 30 cm. This gap should be reduced to 15 cm where children are likely to use the staircase.