If you want to study the content of Whatsapp conversations, you may click on the Whatsapp Group, then choose Email Chat. You will get .txt version of the conversations. With the txt file, you may use for example NVivo or Atlas.ti to do content analysis or thematic analysis (depending on your research objective).
If you want to study the structures of interactions, then you may use Social Network Analysis software.
Group, then choose Email Chat. You will get a .txt copy of the conversations. Using a txt file, for example to do content analysis or thematic analysis (depending on your research objective).