The paper reveals the scientific productivity pattern of authors in the field of Astronomy & Astrophysics research in India and applicability of Lotka’s law in the literature of Astronomy & Astrophysics for the given data set. Data was retrieved from WoS database for this study, a total of 6,363 papers has been published by 2,719 authors during 2013-2017 in straight count of the authorship. Examining the Lotka’s Inverse square (n=2) method as well as general power method (n≠2), (calculating the value of ‘n’ with observed data) was used to test the applicability of Lotka’s law. Goodness of fit test - Chi-Square test and Kolmogorov-Smirnov (K-S) test was also used to measure the viability of Lotka’s law in the field of Astronomy & Astrophysics research in India. The productivity distribution didn’t fit when Lotka’s law was applied in generalized form as well as in its original form on the data set. This confirms that Lotka’s law doesn’t fit to the literature of Astronomy & Astrophysics.