Please correct me if I am wrong this is my own interpretation
Public Limited Co. is defined under section 3 of Companies Act,1956 ,It is mentioned in defination it self that it should have minimum paid up capital of Rs. five lakh or such higher amount as may be prescribed.according to my knowledge public Co. will automaticaly loose its status as public co. if it do not maintain minimum capital as at the initial stage only it can not be incorporated without minimum Capital ,secondly at the time of reduction of capital, Co. can not reduce its share capital without following procedure of section 100,and needs to file form 23 and form 21 to ROC for reducing its capital with the help of these forms and form 5 filed at the every change in the Authorised capital and events mentioned under section 95 of Companies Act,1956 ROC updates master data of Co. which contains information of authorised and paid up capital.
Even PVT LTD CO. require to maintain minimum paid up ccapital of Rs. 1,00,000 as mentioned in Sec.3 (def.)of Act ,ROC maintain record through forms as mentioned above.
Challan generated at the time of filing of these form acts as a receipt,we need to keep hard and soft copy of these form for our record .we should check that master data is accordingly get updated after filing forms regarding capital of the Company for all Co.(Public and private ),there is no other receipt.
for your refernce attaching file containing format of share certificate ,but it should be noted that each Co. can have its own format for share certificate.
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