Regarding joining a central government department as MTS on compassion

once you join the government at group-C level, your promotion will be as per the general rules of promotion in the department. there will be no special treatment on compassionate grounds.
If you are paid well in the current job, might as well continue with it.
in case you are incline to take the job as MTS employee, you can prepare for government service examination on the side. further take the job, see how it goes, build a good network and if a good opportunity comes up take a job in the private sector