Can I use different nameservers for different subdomains?

Yes, You can.

you will have to add the NS records for the subdomain in the DNS Manager for your TLD (Top Level Domain).

For Example: In DNS Manager for TLD add NS records Like.

bla.example.com. 1799 IN    NS  ns1.subhosting.org.
bla.example.com. 1799 IN    NS  ns3.subhosting.org.
bla.example.com. 1799 IN    NS  ns2.subhosting.org.