Don't count your chickens before they hatch
In Marathi कोंबडीची पिल्ले फुटल्यावर मोजा.
This proverb is a direct equivalent, warning against counting on something before it's certain.
Example
"तो आधीच उत्सव साजरा करत होता, पण मी म्हणालो, 'कोंबडीची पिल्ले फुटल्यावर मोजा.'"
