Generally, we usually only answer questions in English or German. But for this one time: We cannot promise compatibility with Mexican networks, please check specifically for the Pixel version you are interested in. Overall so far we know it should be compatible with all non-5G networks, for 5G networks there are some incompatible ones. Further, the last security updates for the Pixel 4a are delivered in August 2023, this is due to the fact that AOSP (the foundation for GrapheneOS) for the Pixel 4a will simply not be updated anymore at this point.