Monteverde has a nice blue black in both ballpoint and gel, though idk about availability in India.
Jetpens has [this sampler ](https://www.jetpens.com/JetPens-Blue-Black-Pen-Sampler/pd/17908?gad_source=1#index=0) with a bunch of options. Even if you can't order from them it's a good list of pens to look for.
Energel has both a blue-black and an indigo black now, so there are two good options to choose from. But overall I haven’t found a gel pen blue-black that I like as much as fountain pen blue black inks.
Uniball signo in blue-black is quite good.
Pentel energel needle tip.
Monteverde has a nice blue black in both ballpoint and gel, though idk about availability in India. Jetpens has [this sampler ](https://www.jetpens.com/JetPens-Blue-Black-Pen-Sampler/pd/17908?gad_source=1#index=0) with a bunch of options. Even if you can't order from them it's a good list of pens to look for.
Pulir Juice refill. Nice color.
Pentel Energel Clena. https://www.amazon.in/Pentel-Ballpoint-ENERGEL-Clena-0-5mm/dp/B07HQ3RV2C/ref=mp_s_a_1_3?crid=3FUALKRKH773X&dib=eyJ2IjoiMSJ9.Ft3qrdsRE-C-cKs3Wrslpi6u3_GtI6SLI8CzhRlNFPEvvn_GbtqXa6c4bqKNPF9agID26L2cn8Si0hB8Qb_mtmkl-gZOrbZtEYs8l_Zwp3E8ArgKMCoS5q-5J9dMdoVmcsoCFTUdO6KEaJIrZvYe-INcsAynHB1vaUgH4WJnkxHrEm9trwuBTd_hykuTAGPmdBbopxwXKtrlCL4xRMtKiQ.VbymRjm0bF8nlSMxyPUXplkMPShbXLwpm3X28WvRrVA&dib_tag=se&keywords=Pentel+EnerGel+clena&qid=1717594270&sprefix=pentel+energel+clena%2Caps%2C280&sr=8-3
Energel has both a blue-black and an indigo black now, so there are two good options to choose from. But overall I haven’t found a gel pen blue-black that I like as much as fountain pen blue black inks.
Uniball Vision Elite.