There are number of simulator is exist for MANET routing protocol such as Exata (Qualnet Extension), NS2, NS3, Glomosim, OPNET. Such as NS2 and NS3 are Command Line based and Qualnet( Exata) is GUI based. If you are not good in command line than you can use Exata. It will give you initial speedup to your work. But it is completely commercial software and others are Open-source. It also gives you emulation support.

I hope that I have solve your query!

Thanks so much Gaurav Singal

To support directional antennas and beam-forming ,i will recommend OPNET. OPNET has antenna pattern editor where you can model antenna according to your own requirements. Then you can test different adhoc networking protocols.Second Opnet is easy to use comparatively to get good results.

Thanks so much Khan M. Asghar

You can use also Omnet, the only problem that I have found with OPNET is the license, I am more confortable with the omnet academic license, but if you university has a opnet license, you can begin to produce results very quickly

Thanks so much Alfonso Ariza

ns2 nd ns3 preferable because its flexible in codec

Thanks so much Ali H. Wheeb

Thanks so much Moussaab Belarbi

As my personal experience, I would recommend you to work on NS2

https://www.researchgate.net/publication/316158581_Development_of_Protective_Scheme_against_Collaborative_Black_Hole_Attacks_in_Mobile_Ad_hoc_Networks

Thanks so much Muhammad Umar