Dottin then stroked an exciting 63 to lead the Windies batting as the hosts got home with four balls to spare.
India had won the opening game last Wednesday by 76 runs before the Windies bounced back on Friday to level the series with a 42-run triumph.
West Indies also won the preceding five-match Twenty20 series, 3-2.
India did not have the best of starts when opener Sulakshana Naik swung seamer Shakera Selman to Stacy-Ann King at square leg to depart for 13 with the score on 22.
Opener Mamatha Kanojia (26) and captain Anjum Chopra (20) then put on 51 for the second wicket to steady the innings before a clatter of wickets left the innings in strife.
Taylor struck with the last ball of her first over to remove Chopra, triggering a slide that saw five wickets tumble for 40 runs as India declined to 113 for six.
However, Harmanpreet Kaur (55) and Jhulan Goswami (30 not out) produced a face-saving stand of 64 for the seventh wicket to rally the lower order.
Kaur faced 84 balls and struck four fours while Goswami hit two fours off 46 balls.
In reply, West Indies were given a sound start of 43 by Taylor (23) and Juliana Nero (19).
The right-handed Taylor, voted Player-of-the-Series, hit two fours in her 60-ball stay at the crease while Nero also counted two fours off 38 balls.
Both batsmen fell as the Windies lost three wickets for as many runs in the space of 25 balls to plunge to 46 for three in the 20th over.
With the run rate slowing, Dottin marched to the crease to plunder India’s bowling, smacking six fours and a six off just 67 balls faced.
She posted 80 for the fourth wicket with captain Merissa Aguilleira (26) to put the Windies in sight of victory and though the innings threatened to implode when both went, the hosts got the two runs required from the last over to spark celebrations.
INDIA
+S Naik c King b Selman 13
M Kanojia b Taylor 26
*A Chopra c Dottin b Taylor 24
M Raj c Knight b Mohammed 4
H Kaur c Campbelle b Daley 55
A Sharma c & b Taylor 3
D David c Knight b Taylor 1
J Goswami not out 30
A Das not out 1
Extras (lb2, w21) 23
TOTAL (7 wkts, 50 overs) 180
Did not bat: E Bisht, G Sultana.
Fall of wickets: 1-22, 2-73, 3-73, 4-89, 5-106, 6-113, 7-177.
Bowling: Selman 10-1-21-1, Munroe 9-0-43-0, Daley 10-1-32-1, Dottin 1-0-16-0, Taylor 10-1-21-4, Mohammed 10-0-45-1,
WEST INDIES
S Taylor b Das 23
J Nero c David b Sultana 19
S Daley c David b Sultana 3
D Dottin c Kanojia b Bisht 63
*+M Aguilleira c Sharma b Goswami 26
S King b Das 11
K Knight c Bisht b Sharma 8
S Campbelle not out 14
A Mohammed not out 6
Extras (w8) 8
TOTAL (7 wkts, 49.2 overs) 181
Did not bat: S Munroe, S Selman.
Fall of wickets: 1-43, 2-44, 3-46, 4-126, 5-147, 6-153, 7-168.
Bowling: Goswami 9.2-2-33-1, Sharma 7-1-19-1, Bisht 10-0-41-1, Das 10-1-29-2, Sultana 8-2-29-2, David 5-0-30-0.