Sub-rule (2) (e) of rule 5 of Notification No. 7165-F(P), dated the 1st July, 2010 covers it. The sub-rule states the following-
“ten per cent of the posts of Lower Division Assistants or Lower Division Clerks borne in the Secretariat Common Cadre of Lower Division Assistant constituted under rule 4 of the West Bengal Services (Secretariat Common Cadre) Rules, 1984 or any Directorate or any of the regional offices may be filled up by promotion from Group D and eligible Group C employees of the Departments or respective Directorates or regional offices, as the case may be, who possess the requisite qualifications.”
for more, please visit the following links.
https://wbxpress.com/west-bengal-service … dre-rules/
https://wbxpress.com/amendment-in-west-b … dre-rules/