Nimbostratus
CirrocumulusI never heard about this company, so I doubt there is any script out there to convert the things. I am just aware of a script to convert Cisco to F5. You will probably have to do the things manually.
One important thing to take into account are the resource types supported by GTM/DNS. It increased in v12, not sure if there was any addition in 12.1.x or 13.0.0.
https://support.f5.com/kb/en-us/products/big-ip-dns/releasenotes/product/relnote-dns-lc-12-0-0.html
"Additional Record Support
This release adds Global Server Load Balancing (GSLB) support for additional resource record types. BIG-IP DNS now supports Wide IPs of resource record types: MX, SRV, and NAPTR. By adding GSLB support for these new record types, BIG-IP DNS can now load balance queries whose responses contain content other than IP addresses. This allows GSLB for responses that are DNS names to other objects in the DNS hierarchy. This new record support is in addition to the already supported Wide IP record types: A, AAAA and CNAME."
Anyway, you can use GTM with BIND. So, BIND can do all resource types (without load balancing, at least intelligently).
You will have to learn how things are done in F5 world, reading the documentation/training/etc... After that, you need to map the object type in that vendor with F5, so what represents a virtual server in that vendor, pools, members, etc...
If is just a small number of services, you can do manually. If a large number, write a script for that could save you a lot of time. If do the script, the easiest way is convert the configuration to tmsh commands, and run those commands in the F5.