Hi Sujatha,
This is year tendency. Perhaps your leave policy doetn't permit carry over of unutilised CL to the next calendar year i.e., 2021. It's a general practice in most of the entities that CL is credited in advance in Jan of a new year and closed by 31st Dec. There's no uniform rule across the board in all entities that CL some follow 10 days and others follow 12 days (on an average one day per month). Thus the unutilised CL remain on 31st Dec. elapses automatically nor allowed to be encashed. Therefore those spare CL till Dec rush to exhaust all CL days before 31st Dec. There is no hard & fast rule as per statue, it's all goes by practices followed by the entities concerned or by HoDs' discretion.
However the purpose of CL is to be availed/meant for emergencies, sudden ill health etc. Thus hardly it's utilised for a couple of days or so. However, if there is no pressure of work/official exigencies permits to be relaxed there's no harm in allowing employees to exhaust all balance days before it elapses. In short if the absence of concerned employees is not expected to cause any hardship/disturbance in their routine/official duties and HoD is satisfied, CL for more days can be permitted.