Analysis of information sources in references of the Wikipedia article "मौर्य राजवंश" in Hindi language version.
Fig. 14.1 Map of the Mauryan Empire
Map 19.1 Magadha kingdom, Mauryan Empire, and Gupta Empire
... killed all his brothers save one and the number of brothers is stated to be 100...This story is obviously inspired by a desire to present a sharp contrast in the character of Ashoka before and after his conversion to Buddhism.
Myths about Ashoka became current shortly after his own time, when Buddhist texts...this resulted in a fantasy that Ashoka killed his ninety-nine brothers.सीएस1 रखरखाव: नामालूम भाषा (link)