@ neha , there are 3 covalent bond in the No3- ion .
and yes , u are correct with the statement that 1 is coordinate as both transfer and sharing occurs their .
it have trigonal planer structure with 120 degree bond angle .
and its sp2 hybridised .
HOPE IT CLEARS YOUR DOUBT
IF U WANT STRUCTURE EXPLANATION THEN LET ME KNOW
ALL THE BEST ..