Deep neural networks based object detectors have shown great success in a variety of domains like autonomous vehicles, biomedical imaging, etc., however their success depends on the availability of a large amount of data from the domain of interest. While deep models perform well in terms of overall accuracy, they often struggle in performance on rare yet critical data slices. For example, detecting objects in rare data slices like "motorcycles at night" or "bicycles at night" for self-driving applications. Active learning (AL) is a well-known paradigm to incrementally and adaptively build training datasets with a human in the loop. However, current AL based acquisition functions are not well-equipped to mine rare slices of data from large real-world datasets, since they are based on uncertainty scores or global descriptors of the image. We propose TALISMAN, a novel framework for Targeted Active Learning for object detectIon with rare slices using Submodular MutuAl iNformation. Our method uses the submodular mutual information functions instantiated using features of the region of interest (RoI) to efficiently target and acquire images with rare slices. We evaluate our framework on the standard PASCAL VOC07+12 [7] and BDD100K [32], a real-world large-scale driving dataset. We observe that TALISMAN consistently outperforms a wide range of AL methods by ≈ 5% − 14% in terms of average precision on rare slices, and ≈ 2%−4% in terms of mAP.