Both Vikram Solar and Adani Solar are Indian Tier 1 solar panel manufacturers. While Vikram Solar imports cells, Adani Solar manufactures cells in India.
Quality wise, both Vikram Solar and Adani Solar are similar and their pricing is also similar. Vikram Solar has a longer track record but Adani Solar has a larger brand behind it and is now manufacturing at a greater scale, giving Adani Solar some advantage.