NCP leader and Maharashtra Deputy CM Ajit Pawar's wife Sunetra on Thursday filed nomination for Rajya Sabha bypolls after she lost Lok Sabha election against sister-in-law Supriya Sule from Baramati seat. The Rajya Sabha seat had become vacant after NCP's Praful Patel resigned in February this year. The Rajya Sabha by-election will take place on June 25.