Ajanābha (Ajanabha) is another name for Ṛṣabha-varṣa (Rishabha-varsha). Later it also came to be known as Bhārata (Bharata). The land is mentioned Anuśāsanaparva (Anusasanaparva) of Mahābhārata (Mahabharata).

Mahābhārata (Kinjawadekar)(13.165.32)
Mahābhārata Vols. 1-43 (Siddhāntabāgīśa)(13.143.32)
Bhāgavatpurāṇa Vols. 1-12(5.4.3; 5.7.3; 9.2.24)