Source: TW
The earliest anthropomorphic images of Indian cult/votive deities in India comes from Bhāgavatism (Tikula, coins of Agathocles, Malhar), Śaivism (Gudimallam Liṅga), and Yakṣa-cult (Parkham Maṇibhadra). These figures date to the 3rd - 2nd century BC.
Jaina bauddha contrast
The earliest Jaina figure is Pārśvanātha from the Pārśvanātha Āyāgapaṭa, dating to the first century BC.
There is no anthropomorphic inage of Buddha before 1st century AD Mathurā & Gandhāra, which postdates even images of Skanda on Yaudheya coins.
The Sāñcī Stūpa and Barhut Stūpa depict Buddha in aniconic form and depict Indra/Śakra and Brahmā with nondescript characteristics, implying that a particular iconography had not yet developed.
Cult epigraphy
The Mora Well inscription referring to pratimās of the Vṛṣṇi Pañcavīras (i.e. Saṅkarṣaṇa/Balarāma, Vāsudeva/Kṛṣṇa, Pradyumna, Sāmba, and Aniruddha) and the Vasu Doorjamb inscription referencing a toraṇa that was erected at the great temple of Vāsudeva were discovered at Mathurā.
Megasthenes also references the cult of “Heracles” at “Methora” and “Kleisobora.”