In Jain tradition, a few souls are specially remembered for attaining keval gyan while still in gṛihastha (householder) status, i.e., before formally taking dikshā. The main names commonly accepted are:

1. Bharat Chakravarti

- Son of Bhagwan Rishabhdev (Ādināth), first Tirthankar of current avasarpinī. - Attained keval gyan while still a chakravarti (emperor), i.e. in gṛihastha āshrama. - After keval gyan he later took saṃyama and finally attained moksha.

1. Shrenik (Bimbisār) – according to some Śvetāmbara accounts, not all

- King of Magadh, great śrāvaka of Bhagwan Mahāvīr. - It is universally accepted that he will attain keval gyan and moksha in the future as king Meghrath in the next time-cycle. - A minority narrative says he had a brief manifestation similar to keval-jnān while in gṛihastha, but this is not the standard, unanimously accepted doctrine; most ācāryas clearly place his keval gyan in future existence, not now.

1. Other examples

- In some kathā–granth and local traditions, a few chakravarti or vidyādhars in earlier time-cycles are said to have attained keval jnān before formal renunciation, but detailed names and lists differ between texts and sects, and are not always treated as main doctrinal points. - The clearest, undisputed example repeatedly mentioned in śāstra and pravachans is Bharat Chakravarti.

Digambar vs. Śvetāmbara view

• On the principle:

Both Digambar and Śvetāmbara agree that in theory a soul can attain keval gyan even in gṛihastha–dasha, if all ghātiyā karmas are destroyed. Formal external dikshā is not an absolute pre-condition; inner vītarāgta is.

• On names:

- Bharat Chakravarti as gṛihastha-kevalī is accepted in both traditions. - Details of other possible gṛihastha-kevalīs may differ in lists, purāṇas, and commentaries; they are not as unanimously highlighted.

So, if you are looking for the main, certain example, the answer is:

> Bharat Chakravarti is clearly accepted as a kevalī who attained keval gyan in gṛihastha dasha.

You can read a bit more about such personalities and Jain concepts here