Why did BJP-SAD talks end? Will Bittu and Rinku's entry help BJP? 

The BJP-SAD is not reviving its alliance. The aspects of what went wrong are seat-sharing, fearing backlash among Sikh voters, and concerns over vote transfer. Congress MP Ravneet Singh Bittu and AAP MP Sushil Rinku joined the BJP for the seats that SAD previously contested; however, Bittu's entry doesn't address the BJP's issues with distrust among Sikh and Dalit voters.