In Jain Dharma, diksha is not taken just by emotion or temporary inspiration. It is generally considered suitable when deep vairagya bhav becomes stable, sincere, and supported by right understanding.

What decides diksha?

Mainly these inner qualities are seen:

• Strong vairagya: true detachment from worldly life, not momentary sadness or disappointment
• Samyagdarshan / right faith: firm श्रद्धा in Jain tattva, karma, moksha-marga
• Samyagjnan: some clarity about the life of renunciation and its disciplines
• Inner readiness for restraint: willingness to give up possessions, comfort, attachment, and personal independence
• Capacity to follow vows: ability to live under strict discipline, obedience, simplicity, and humility
• Guidance of a योग्य गुरु: a proper acharya or guru examines whether the person is fit

Can phases of vairagya bhav be a criterion?

Yes, vairagya bhav is an important criterion, but only having a phase of vairagya is not enough.

Because sometimes vairagya comes due to:

• grief,
• failure,
• fear,
• temporary disgust with life,
• or emotional stress.

Such vairagya may be real in feeling, but it may not yet be stable vairagya. For diksha, Jain tradition looks for deep, lasting, and mature vairagya, not only a passing stage.

In simple words

A person should take diksha when:

• worldly attachment has become genuinely weak,
• the mind is steady in renunciation,
• the soul is prepared for severe discipline,
• and a competent guru approves the readiness.

So yes, vairagya bhav is a major sign, but diksha is decided by the maturity, firmness, and authenticity of that vairagya, not by a temporary phase alone.

If you want, I can also explain this from the view of Shwetambar and Digambar traditions.