Short answer: Yes, you can undertake a Palitana yatra during Chaumasa, but with careful adherence to Chaumasa conduct and local guidance.

Key points to keep in mind

• Chaumasa (the four-month monsoon period) is primarily a period when monks observe Chaturmas with strict adherence, and many Jain lay followers also practice restraint and increased mindfulness during this time.
• For lay devotees, visiting temples and doing pilgrimages is generally allowed, but many communities prefer travelers to exercise restraint: avoid unnecessary or excessive travel, travel slowly and respectfully, and practice ahimsa (non-violence) especially toward living beings encountered in monsoon.
• Palitana involves substantial travel and climbing steps; plan your schedule to minimize harm to insects and plants, and be mindful of the environment during the rainy season.
• Digambar and Śvetāmbara communities may have slight regional or temple-specific practices during Chaumasa. If you have a guru, local priest, or temple authority, consult them for any site-specific prescriptions.
• If you wish to keep to stricter Chaumasa norms, you can charity-practice, perform puja, and visit temples without extended uninterrupted travel, or choose a shorter or more convenient window within Chaumasa.

Practical tips

• Speak with your local Jain sangh or the Palitana temple authorities to confirm any site-specific Chaumasa guidelines for pilgrims.
• Bring appropriate rain gear, sturdy footwear, and follow responsible travel to protect the monsoon environment.
• Maintain a simple, non-violent itinerary: modest meals, minimal possessions, and careful handling of all creatures you may encounter on the journey.

If you’d like, I can point you to guidance specific to Chaumasa practices from Jain sources or community authorities.