@suhanichandrag please see provisioning thread at https://community.blynk.cc/t/blynk-provisioning-fails-with-arduino-core-master-branch/15944/1
Which version of the core are you using? I am guessing 2.3.0.
From the details you sent me it looks like you are using the myPlant provisioning. You should switch to the Template_ESP8266 found in your IDE as I believe it has a few subtle differences to the myPlant sketch.
Start with a new project, just a single button on V0 and everything set at NCODEMCU including the sketch edit shown below.
//#define USE_SPARKFUN_BLYNK_BOARD // Uncomment the board you are using
#define USE_NODE_MCU_BOARD // Comment out the boards you are not using
Please provide Serial Monitor data when you switch to the Template_ESP8266.