Hi
I can see that your VMs are in subnet 192.168.1.0/24 (.201-.254) and other PC on network are in same subnet (.2-.200).
Some options that I can think:
1. PVLAN
Configure Private VLAN on your dvSwitch.
Requires dvSwitch + Private VLAN-Aware Physical Switch
2. Configure Firewall Rules on your Internet Modem (if available)
3. Configure Traffic Filtering on dvSwitch.
vSphere 5.5 Documentation Center - Traffic Filtering and Marking Policy
Requires dvSwitch 5.5
See also this blog post: Virtualization The Future: Traffic Filtering and DSCP Marking in vSphere 5.5
If you prefer to configure on vCenter (on vSwitch), then you can use option 3.
Bayu Wibowo | VCIX6-DCV/NV
Author of VMware NSX Cookbook http://bit.ly/NSXCookbook
https://github.com/bayupw/PowerNSX-Scripts
https://nz.linkedin.com/in/bayupw | twitter @bayupw