argument after reserving judgement

With reference to your query, this is well explained in Application under Order 18 Rule 2 Clause 4. Reopening of the case to record evidence.  It has been clarified that once the judgement has been reserved for judgement, no further action is permissible, if final arguments has been heard and the matter is in final process of judgement. 

Case reference of Karnataka High Court 

Rabiya Bi Kassim M. vs The Country Wide Consumer... on 5 April. 2004