Layered transition-metal oxyhalides provide a versatile platform for studying the interplay between electronic correlations, reduced dimensionality, lattice distortions, and magnetic order. In this project we will use electronic-structure calculations based on DFT+DMFT, to investigate correlation effects in CrOCl, VOCl, and potassium-intercalated KxVOCl. These materials are not strictly two-dimensional, but their structures consist of strongly bonded transition-metal oxyhalide layers separated by large van der Waals gaps, leading to quasi-two-dimensional electronic and magnetic behavior. A central motivation is that electronic correlations in these systems are subtle and cannot be regarded as a simple correction to conventional DFT. In CrOCl, different treatments of exchange and correlation can qualitatively change the predicted magnetic ground state: standard DFT+U parametrizations may favor a ferromagnetic state, whereas plain PBE and more carefully parametrized approaches recover the experimentally observed antiferromagnetic order. This demonstrates that the balance between direct exchange, superexchange, orbital polarization, and correlation effects is delicate. DFT+DMFT provides a natural extension of these studies by treating local dynamical correlations beyond static DFT+U and by allowing us to assess whether the insulating state and magnetic interactions are governed primarily by band-structure effects, static orbital polarization, or genuine many-body correlation physics. VOCl and K-intercalated VOCl add a complementary perspective. In pristine VOCl, stronger correlation effects and narrower d-derived bands make the electronic structure more sensitive to the treatment of on-site interactions. Potassium intercalation provides an experimentally controlled way of tuning the electron count, lattice structure, and magnetic exchange pathways. Recent work shows that K intercalation drives VOCl from antiferromagnetic order to spin-glass behavior at intermediate K concentrations and to a ferrimagnetic or canted antiferromagnetic state at high intercalation. Theoretical calculations indicate that this evolution is associated with competing ferro- and antiferromagnetic exchange interactions, magnetic frustration, and nearly degenerate metastable states. The requested computational resources will enable systematic calculations across composition, structure, pressure, and temperature, with particular focus on the correlated transition-metal d states. The project will clarify how local electronic correlations influence orbital occupations, insulating gaps, local moments, spectral functions, and magnetic exchange interactions in quasi-two-dimensional oxyhalides. This is essential for predictive modeling of layered correlated magnets and for guiding future experimental efforts to control magnetic states through intercalation, strain, dimensional confinement, and chemical design.