In Jainism, karmic results arise from the combination of your thoughts (mental state), speech, and actions. What you call “gau jatra” (and doing it 6 times, 3 times, or more) will influence your karma mainly through intention, adherence to ahimsa (non-violence), truth, restraint, and the overall purity of your conduct.

Key points to understand:

• Karma is not erased simply by repeating a ritual. Past karmas influence your present abilities and experiences, but disciplined practice can gradually purify the mind and reduce the accumulation of new karma.
• If the practice is performed with proper intention (aiming for self-purification, non-harm to living beings, and detachment from ego), it can help burn or burnish karma more constructively. If it is done with selfish motives, pride, or causing harm, it can generate new karmas.
• Repetition itself is not inherently good or bad; what matters is your inner resolve, ethical conduct, and how you manage passions like pride, attachment, or anger during the practice.
• There are differences in interpretation between Digambara and Śvetāmbara traditions on various vows and austerities. If you want, I can explain how each tradition views a specific vrata or practice you’re considering.

In short: your karmic outcomes from doing gau jatra (or any vrata) depend on your inner state and fidelity to Jain ethical guidelines. Repeated practice can aid purification if done with sincere, non-harmful intention and strict self-control; it can also create new karma if driven by ego or harm.