Active telegram groups for ICO investment?, I don't think there will be any left because they have been disbanded as ICO is now forgotten; yes forgotten owing to how investors were treated which of course was terrible. Seriously it would be better to save your strength and energy for more better fundraising options like IEO where you have a higher chance of succeeding than in ICOs where you won't know your fate. Also, even if you find, be careful as scammers are always active looking for who to steal from and ICO affords them the opportunity to do so.
Perhaps the intention of the OP is IEO because ICO is rare nowadays, IEO is also far from being terrible with ICO if you participate in the exchange of low-reputation IEO and volume manipulation. Participate in top IEO exchanges such as Binance even though it is now rare to open a new IEO.