For a 1st birthday celebration in Tiruchirappalli, you can choose culturally relevant return gifts. One popular option is to give small traditional items like intricately designed kolam (rangoli) stencils, brass or clay lamps, or even silk thread bangles. These items reflect the rich cultural heritage of the region and can be cherished by the guests.

Additionally, you can consider practical gifts such as customized baby photo frames, personalized keychains, or small plant saplings, which symbolize growth and prosperity. To make the return gifts more memorable, consider adding a touch of local flavor by including some regional sweets or snacks like banana chips and Tiruchirappalli's famous Thuvaiyal, which can add a delightful local touch to your gifts.