As of my knowledge, Network Simulator 2 (NS2) repositories with swarm intelligence algorithms are not specifically located in one place. Researchers and developers may contribute their NS2 modules or extensions related to swarm intelligence to various open-source communities or personal websites.

Here are a few sources where you might find such resources:

GitHub: It is the largest platform for open-source projects. You can search for NS2 projects or scripts related to swarm intelligence algorithms. Note that the quality and documentation of repositories can significantly vary.

ResearchGate: Many researchers upload their algorithms and scripts to ResearchGate. You can search for NS2 projects here as well.

SourceForge: It is an open-source community resource and can have NS2 related projects.

Google Scholar or IEEE Xplore: Some published papers about swarm intelligence in NS2 may provide source code in the supplementary materials or upon request.

Remember to always check the license of the software before using it. Some authors might restrict usage or require certain conditions to be met.

Remember to use relevant keywords related to the particular type of swarm intelligence algorithm you are interested in, such as "Ant Colony Optimization", "Particle Swarm Optimization", "Bee Algorithm", etc., when searching for repositories.

Please note that as of 2021, NS2 has largely been replaced by NS3, and you might find more recent and well-maintained modules and extensions for NS3.

GitHub, GitLab, Bitbucket, and SourceForge are platforms for code sharing and collaboration. Search for Swarm intelligence, NS2, Reclassification algorithms, and Routing algorithms. In addition to these keywords, you may also consider searching for specific swarm algorithm keywords such as Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO), Genetic Algorithms (GA), and others. Combine these keywords with "NS2" to find repositories that implement these algorithms in NS2.