I think i should be more clear on this
1. yes, i can understtand that in HANA studio-> backup catalog if we select the catalog ->right click and then delete option is there. -> I am not at all concerend about this.
2. I am not bothered about the data & log backup's becoz every customer will keep it external disk/tapes.
3. What i am bothered is
There are many logs(transaction logs) that are getting generated for every 5 mins (savepoint_tim = 300sec not sure about the correct parameter name but, it will be like that.). These are getting stored from many long time under /$dir-instance/backup/log---- I am bothered about these logs.