Here is the list of the Best Power Banks you can get for your Micromax Yu Yureka from the online stores:
1. COOLNUT® Exclusive Design High Capacity 10400mAh Power Bank With 4 LED Power Indicator ,Reliable, Light Weight, Mini Portable External Battery Charger for Apple iPhone5, iPhone6, iPhone6+, iPhone6s, iPhone6s+, Samsung, HTC, MI, Blackberry, Nokia, Moto, Asus, Lenovo, Xiaomi, Letv, Oppo & all others Android and Smartphones by FNS
Price: Rs.1,299. You will get this from Amazon.in
2. Lenovo PA10400 Power Bank 10400 mAh Lenovo PA10400 Power Bank.
Price: Rs. 1,299. You will get this from Flipkart
3.Debock Yu Yureka Power bank 10400 mAh (White)
Price: Rs. 1,849. You will get this from Flipkart
4. GooDiT Mi10000rc_bl Universal Power Bank 10000 mAh
Price: Rs. 1,199. You will get this from Flipkart
5. Xiaomi mi power bank 12000mAh silver colour for Samsung/HTC/Apple/Micromax
Price:Rs. 1,399. You will get this from Ebay.in
From the above listed Power Banks, user review says that the Xiaomi Mi Power Bank would be the best for your Micromax Yu Yureka model.