In Jain tradition there isn’t one single “Diwali aarti song” that everyone must sing. On Diwali (Mahavir Nirvan Kalyanak), Jains usually do:

• Namokar Mantra
• Mangal Divo / Mangal Diva Aarti
• Other Jain stavans or aartis praising Bhagwan Mahavir and the Tirthankars

A very common aarti-style song used on Diwali evening is “Mangal Divo” while lighting the diya.

Example: “Mangal Divo” (popular Jain aarti with diya)

Transliteration (main part):

Mangalam Bhagavān Vīro Mangalam Gautama Prabhu Mangalam Sthūli-bhadra-ādyāḥ Jaina-dharmo mangalam

Om hrīm shrīm arham Om Namo Arihantāṇam Om Namo Siddhāṇam Om Namo Āyariyāṇam Om Namo Uvajjhāyāṇam Om Namo Loe Savva-sāhūṇam

Eso pañcha Namokkāro Savva-pāvappanāsano Mangalāṇaṃ cha savvesiṃ Padhamam havai maṅgalaṃ

Deepak jyot parabrahma Parabrahma jyot deepak Jo mein prabhu tum mein Āp jyot mein āp

Simple meaning (essence):

• “Auspicious is Bhagwan Mahavir, auspicious is Gautam Swami,

auspicious are all great acharyas like Sthulibhadra, and auspicious is Jain Dharma.”

• “I bow to Arihants, Siddhas, Acharyas, Upadhyayas, and all sadhus in the world.

This five-fold Namokar Mantra destroys all sins and is the highest auspicious thing.”

• “The light of the lamp is like the supreme pure consciousness;

that pure light is in you and in me – we ourselves are that inner light.”

On Diwali night, Jains usually:

• Light a diya in front of Mahavir Bhagwan
• Recite Namokar Mantra and/or Mangal Divo like above
• Remember Mahavir Bhagwan’s Nirvan (moksha) and the light of true knowledge, not fireworks

You can see more related Jain aarti content here and here