In a mantra the word janitā is formed irregularly by the elision of ṇi before the affix tṛ with the augment iṭ ,
Thus यो नः पिता जनिता ॥ Otherwise जनयिता in secular literature. It is an exception to 6.4.51.,
जनिता मन्त्रे
Adhyāya 6 · Pāda 4 · Rule 53