Topological insulators (TIs), which are insulating in bulk and conducting on surface due to a protected time-reversal symmetry (TRS), have become of great interest recently. The TRS can be broken by elemental magnetic doping. 3D TI Bi2Se3 is one such example. One attractive direction could be the use of nanostructures, wherein the surface-to-volume ratio is high. Recently, we synthesized Co- and Dy-doped Bi2Se3 hexagonal nanoplates (NP's). Magnetization measurements indicated the occurrence of a ferromagnetic phase at very low temperatures (T), while the NP's are diamagnetic or paramagnetic otherwise. Weak Co and strong Dy moments were found to accompany this behaviour. Thus, there is an unsystematic magnetic behaviour of the NP’s. We propose measurements of local magnetic properties using MUSR at varying T and magnetic field to gain further insight into the problem.