Risks in offshore custom software development include communication challenges, cultural differences, and potential quality issues. These can be mitigated by choosing an experienced vendor with a proven track record, setting clear expectations, and establishing robust project management practices. Regular communication, including video calls and progress updates, helps maintain alignment. Understanding cultural differences and working hours ensures smoother collaboration. Additionally, implementing a strong quality assurance process and setting up key performance indicators (KPIs) ensures that the project stays on track and meets the desired quality standards.