Answer

Yes, you may recite Jain mantras at night with devotion, purity of intention, and respect.

However, the mantra you wrote — “om hrim shrim arham aa si ause namah” — does not appear to be a clearly established standard Jain mantra in this exact form.

So, I should say carefully: Sorry, I can only provide information that is clearly established within Jain tradition.

Explanation

In Jain Dharma, sacred recitation such as:

• Namokar Mantra
• Arham mantra
• Om Hrim Arham Namah

is generally considered suitable at any peaceful time, including night, if done respectfully.

At night, it is good to:

• Recite with a calm and pure mind
• Sit in a clean place
• Avoid careless or casual chanting
• Keep the feeling of reverence toward Arihants, Siddhas, and Dharma

Spiritual Understanding

The purpose of mantra recitation in Jain Dharma is not worldly gain, but purification of thoughts, reduction of passions, and turning the soul toward right faith, right knowledge, and right conduct.

Takeaway

You may do Jain mantra recitation at night, but for the exact mantra form, it is best to follow a mantra clearly taught by your Jain tradition or ask a knowledgeable Jain guru, sadhu, sadhviji, or scholar.