So by chanting Hare Kṛṣṇa mantra one becomes free from sinful reaction. Not only that; he becomes very soon a devotee. Yatas tad-viṣayā matiḥ. Yataḥ means simply by chanting. Here it is clearly stated, nāma-vyāharaṇam, chanting of the holy name. Vyāharaṇam means chanting; nāma-vyāharaṇaṁ viṣṇoḥ, "of Lord Viṣṇu." So not only he becomes free from all sinful reaction of his life, but yatas tad-viṣayā matiḥ: his mind becomes fixed up in the lotus feet of Kṛṣṇa.
So try to understand what is the result of chanting, simply by chanting Hare Kṛṣṇa mantra. Therefore Caitanya Mahāprabhu recommends, harer nāma harer nāma harer nāmaiva kevalam (CC Adi 17.21). So without offense, without committing offense, if we regularly chant this Hare Kṛṣṇa mantra, then we remain freed from all sinful reaction of life and our attachment for the Supreme Lord in devotional service increases. Yatas tad-viṣayā matiḥ.