I have some scRNA seq data, and I want to check and see which transcripts for a specific gene (it has about 5 alternative transcripts) are expressed in a specific cell type. Is that possible?

This is not related to Bioconductor. Generally, biostars.org is a good place to ask. In brief, scRNA-seq is commonly analysed on gene and not transcript level since counts per gene are already low, and even lower for transcripts, plus in end-tagged data ambiguity of reads is often high between transcript per gene. Common preprocessing tools return gene level, so you would need to tweak things.