You can go through it. You need to have only coordinates and topology of the system. This link will be helpful. http://www.mdtutorials.com/gmx/complex/01_pdb2gmx.html

Thanks for your answer Tasneem Kausar

For continuous of simulation, you should take the final gro file of your last simulation and take all the itp and top files and do simulation. At the end Just join the two trajectories.

Or

If you have cpt file of your previous simulation, then just use -cpi append flag on mdrun command and continue the simulation.

Krishnendu Bera Thanks for your answer. I want to know can I join two .itp files that I got from a paper (bot of the are base on AMBER FF) and perform a simulation on the nanosheet@drug complex without including the parameters in the working force field?

Best.

Farideh

Yes! you just include (mention) the itp files inside your topology file and keep the itp inside the same directory.

Krishnendu Bera Thank you for your time and answer!