The percentile of the Close would probably be 100*(Close-Low)/(High-Low) - but for what purpose would you need that???

For e.g.,5min bar contains 300 sec.How would you break those second down into %,from the opening of the bar to its close?

percentage equals: number of seconds divided by 300 multiply by 100. eg 75 seconds = 75/300*100=25% Likewise if you wish to know how much percentage a small piece of a bar is. partial length of bar divided by full length of bar times 100 equals the percentage.