Hello. my router is doing load balancing with routing mark. i have also static routing for dns of 1st and second isp. but when i traceroute the it shows that 1st isp dns going throug 2nd isp. why my static routing not working? All of them distance is 1.
Here is my routing table. Is there any work with ip route rule?

[admin@MikroTik-2] /ip route> print
Flags: X - disabled, A - active, D - dynamic, C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme,
B - blackhole, U - unreachable, P - prohibit
# DST-ADDRESS PREF-SRC GATEWAY DISTANCE
0 A S 0.0.0.0/0 117.103.81.73 1
1 A S 0.0.0.0/0 122.102.35.77 1
2 S 0.0.0.0/0 111.92.249.225 1
3 A S ;;; added for DNS
122.102.32.226/32 122.102.35.77 1
4 A S ;;; added for DNS
117.103.80.91/32 117.103.81.73 1
5 A S ;;; added for DNS
117.103.80.90/32 117.103.81.73 1
6 A S 0.0.0.0/0 117.103.81.73 1
122.102.35.77
122.102.35.77
111.92.249.225
111.92.249.225
7 ADC 10.0.3.0/24 10.0.3.1 ether4 0
8 ADC 10.0.10.0/24 10.0.10.1 ether4 0
9 ADC 111.92.249.224/28 111.92.249.226 ether5 0
10 ADC 117.103.81.64/29 117.103.81.65 ether5 0
11 ADC 117.103.81.72/30 117.103.81.74 ether1 0
12 ADC 122.102.35.76/30 122.102.35.78 ether2 0
13 ADC 122.102.35.80/29 122.102.35.81 ether4 0
14 ADC 122.102.35.176/28 122.102.35.177 ether4 0
15 ADC 192.168.30.0/24 192.168.30.1 ether3 0
16 ADC 192.168.66.0/24 192.168.66.1 ether4 0

I am using RB750 for load balancing with 3 WAN port. Is RB750 processor sufficient for it or I need higher configuration routerbord?

If you are load balancing between different ISP, I would suggest that you better use public DNS Servers
instead of those of the ISP. And then, let your routerboard act as DNS server for your clients.

Anyway, in your configuration, if you are using PCC for load balancing, you are marking connections in prerouting chain, thus
marking connections of router itself destined for your ISP DNS servers. So this connections would go through
the route with the respective mark routing instead of the static route you have created.