You have to buy a dictionary which has gender of words.

you know name is female when normally it ends with 'AA', this is not strict rule, but normally you can use it slowly you will pick exception rule. eg: Jatraa (festival) is feminine, kathaa (Story) is fem, Geeta (book) is fem. Exception to above rule is if previous char is also AA, and last char is AA then it turns masculine - eg: AAmBaa (mango) is masculine, Maanja (kite-rope), KaaKa (uncle) is masculine. similarly words ending with EEI are feminine - Aeei (mom), Baei (lady), Maaei(sister), Katrie ( scissor) if word ends with single A and if previous char is AA then also it is feminie eg Ratraa (night) there are 5-6 fixed rules, as to depending on word prononciation it turns mas or fem, will try to dig it from grammer book if i get hold of it