This structural illustration is after energy minimization. Which structure should I take for further tensile mechanistic deformation, time step 0 or time step 29000?
If you minimized the energy of a structure, then I guess you should use the minimized structure and not the initial structure.
Note that it is really only a guess on my part. Your post does not contain enough information about your system.
This is a bimetallic Ti50Al50 crystalline structure for tensile deformation.
That is not really a question about LAMMPS but about the science of your research.
This means the question is off-topic here and you should rather discuss this with your adviser.