The phrase "a rather complicated process" is correct and usable in written English.
You can use it to describe a procedure or method that involves multiple steps or complexities.
Example: "The project requires a rather complicated process to ensure all aspects are thoroughly addressed."
Alternatives: "a quite complex procedure" or "an intricate process".
This proposal has to be discussed and later adopted in a rather complicated process involving the European Parliament and the EU Council of Ministers.
The monocytes quickly mature into macrophages, and through a rather complicated process the LDLs are oxidized, mainly due to the pressure of the free radicals.
The release of a drug from the polymeric nanoparticles is a rather complicated process (Reddy et al. 2006; Panyam and Labhasetwar 2004).
Location of immigrants is not randomly assigned, but it is a rather complicated process that depends on many factors that may be related to criminal activity.
It is a rather complicated process as many factors must be controlled in order to produce good and environmentally safe fertigation practices.
Though the question of whether physical components or cognitive processes are more effective in the reading process has been answered differently by various researchers, the consensus upon the nature of this activity is the fact that it is a rather complicated process.
There are plans to change to absolute primogeniture in Spain through a rather complicated processes, as the change entails a constitutional amendment.
It should be noted that the isentropic and other approximations as used in our simulations, on one hand, have simplified the actual rather complicated process of the gas jet through the Laval nozzle; however, they have unavoidably resulted in some deviations from the actual process [15].
Activation of coagulation is a rather complicated multifactorial process initiated with interaction of PLTs, vWF and the vessel wall.
However, this multi-step method involves rather complicated processes.
The selection of the most appropriate hotel entails a rather complicated decision-making process.
