The maximum amount that you can invest in any AMC (all funds combined together) is Rs 50,000 per year. You can do your eKYC with any good mutual fund app completely online.
Once your investment crosses 50k in a specific AMC, you must have full KYC. Another strategy to delay this (and thus avoid full KYC) is to do SIPs in two different AMCs so that you don’t cross 50k in any one AMC per year.
It is advisable to complete your full KYC so that this limit can be relaxed and you can make investment in any AMC.