i want to block all dns queries from lan to Internet so only server allowed to make dns requests so i need rule to dns requests from eth0 to Internet allowed, lan to eth1 allowed, but lan to Internet rejected
Did you try reading the iptables manual?
iptables -A FORWARD -i lan -o internet -p tcp --dport 53 -j REJECT
iptables -A FORWARD -i lan -o internet -p udp --dport 53 -j REJECT