Answer

No, not as a standard Jain rule. 2 Namokars are not traditionally treated as an exact replacement for 1 Mangalashtak.

Explanation

They are different prayers with different forms and meanings:

• Namokar Mantra is the most fundamental Jain mantra of reverence.
• Mangalashtak is a separate auspicious stotra used for praise and मंगल भावना.

So, if a ritual or vidhi specifically asks for Namokar, it should be done as Namokar. If it asks for Mangalashtak, then recite Mangalashtak.

Spiritual Understanding

In Jain Dharma, prayer is not only about counting lines or matching numbers. It is also about:

• correct reverence,
• right intention,
• and following the tradition properly.

A mantra should not be casually “converted” into another prayer unless your guru, vidhi, or community tradition specifically allows it.

Takeaway

Short answer: no, they are not direct substitutes. Both are sacred, but they are not equal replacements.