Buy back of securities or shares

Someone pls explain how to perform Tests of Buy back of shares as per a) Shares Outstanding Test , b) Resources test..

Because Module says ---->> Provision for the buy back is equal or less than twenty five percent of the total paid-up capital and free reserves of the company. (Silent on Shares Outstanding Test)

RTP says  ------>> Provided that no offer of buy-back for fifteen per cent or more of the paid up 
capital and free reserves of the company shall be made from the open market. (Again, Silent on Shares Outstanding Test)

So what percentage shoud I take for only Share Outstanding Test.... i.e., what percentage of only Equity Share Capital is allowed to be bought back??

Thanks.