Hi @gsourav577,
Please have a look at the formatting and posting guidelines on this topic to help people read your input file and get some general advice on how to formulate your question and investigate your issue.
If you are new to lammps and DPD, the best place to start is the relevant literature, the manual and more importantly, get feedback to your questions from an experimented advisor/colleague face to face.
After a quick look at your input, I can already see that you are using NVT with DPD pair_style which is unnecessary. The random and dissipative forces of DPD take care of thermostatting your system. This is why you provide an input temperature. Since those forces depend on relative velocities of interacting particles, using a fix like setforce 0 0 0 seems ill advised to me. The way I’ve seen such surfaces thermalised using DPD was through tethering forces like in this article. The NVE integrator should be enough.
Overall I think you need to carefully think about your setup and look for suitable parameters in the literature.