Efficient energy transfer coupled with electron transfer remains the bottleneck in designing of a semiconductor photocatalysts with augmented photocatalytic efficiency. In order to achieve so, doping of catalytically active transition metal ions (Pd, Fe, Cu, etc.) is done quite frequently with a presumption that these ions can facilitate electron (charge) transfer processes. However, the complexity involved in excited state energy transfer processes of transition-metal ion doped nanocrystals are not investigated in detail. Thus, it has intrigued us to investigate the photophysics and photochemistry of Nickel(II) and Cobalt(II) ions-doped cesium lead bromide nanocrystals (Scheme 1). Ni(II) ion doped nanocrystals are found to retain intense emission and offer remarkable stability. The role of dopant, Ni(II) ions having the smallest transition metal Shannon radii in modulating photoluminescence properties of perovskite nanocrystal has been attributed to structural rigidity of crystal favoring carrier-dopant spin exchange interactions. Here, we have selected Ni / Co-doped nanocrystal as a donor and organic dye, Rhodamine B as an acceptor for understanding the energy transfer processes. The basis of this donor-acceptor selection stems from the observation of photocurrent generation by organic dyes in quantum dot solar cells. Moreover, recent studies on Förster Resonance Energy Transfer (FRET) between pristine cesium lead bromide perovskite and organic fluorophores indicate that singlet energy transfer efficiency is dictated by-(i) binding constant of acceptor with nanocrystal's surface, and (ii) overlap integral, J(). Binding constant of a donor-acceptor system is very intrinsic and thus plays a pivotal role in determining the efficiency of energy transfer, whereas overlap integral, a theoretical concept provides a rationale for modulation of energy transfer efficiency for a set of systems. However, it has been presumed that donor-acceptance remains unchanged. Thus, it is pertinent to understand the role of crystal facets in regulating the binding constant vis-à-vis energy transfer from transition metal-ion doped perovskite nanocrystal to organic fluorophore. In this work, we have synthesized Ni:CsPbBr3 (Ni:PNC) and Co:CsPbBr3 (Co:PNC) and Ni:Co:CsPbBr3 (Ni:Co:PNC) perovskite nanocrystals by using a modified hot-injection method.