@Kamta Kesharwani to run simulations with xschem you need to install xschem, open_pdks and it's prerequisites and of course ngspice. After installing open_pdks, create an empty directory, copy the file

.../share/pdk/sky130A/libs.tech/xschem/xschemrc

into it and start xschem from this directory. Open_pdks will automatically download all sky130 symbols for xschem.